Canton, Massachusetts · Saved source text
Article 12 Motion 10
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Source page 1
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March 8, 2017
Certified Mail No. 7013 2630 0000 0461 6599
Return Receipt Requested
Town of Canton
c/o James Donovan, Town Engineer
801 Washington Street
Canton, MA 02021
Subject: CERTIFICATE OF NON-COMPLIANCE and DAM SAFETY ORDER
Dam Name: Reservoir Pond Dam
Location; Canton
N ational ID No: MA00166
Known Condition: Poor
Hazard Potential: Significant
Dear Mr. Donovan;
In accordance with 302 CMR 10.08, the Department of Conservation and Recreation (DCR),
Office of Dam Safety (ODS) has determined that Reservoir Pond Dam does not meet
accepted dam safety standards and is a potential threat to public safety. Therefore, DCR
hereby issues a CERTIFICATE OF NON-COMPLIANCE and DAM SAFETY ORDER.
ODS records indicate that the Town of Canton is the Owner of the Reservoir Pond Dam,
National Inventory of Dams No. MA00166. ODS classifies the dam as a Large Size,
Significant Hazard Potential Structure. Significant Hazard Potential Dams are dams that
may cause the loss of life and property damage in the event of dam failure,
COMMONWEALTH OF MASSACHUSETTS EXECUTIVE OFFICE OF ENERGY & ENVIRONMENTAL
A FFAIFS
Department of Conservation and Recreation Charles D. Baker Matthew A, Beaton, Secretary
251 Causeway Street, Suite 600 ~~ Governor Executive Office of Energy &Environmental Affairs
Boston MA OZ 114-2119
617-626-1250 617-626-1351 Fax ~_,,;~ Karyn Polito Leo Roy, Commissioner
Lt. Governor Department of Conservation &Recreation
wwH~.mass.gov/dcrSource page 2
On January 5, 2017, an inspection of the Reservoir Pond Dam was performed by
your engineering consultants Stephens Associates. As a result of this inspection, the
dam was determined to be STRUCTURALLY DEFICIENT and in POOR condition,
The dam has been found to be in need of repair, breaching or removal to bring the
dam into compliance with dam safety regulations,
The CERTIFICATE OF NON-COMPLIANCE is based on the above-referenced Inspection
report results which listed the observance of many deficiencies, including but not
limited to.
1, Uncontrolled seepage around and beneath the Primary Spillway:
During dye testing, Stephens Associates (SA) observed dyed water
flowing from the pond into the riprap on the right upstream side of
the Primary Spillway, immediately in front of the sheet piles. The
Town reported that, on previous occasions (at lower water
elevations), dye also entered the stone masonry wall right of the
Primary Spillway just above the concrete cap of the sheet piles, and
SA observed numerous, disproportionate leaves settled in that
location, suggesting water inflow. SA observed the dye discharging
into the culvert at the following locations. Other than the dye, the
water was clear (not turbid) in the following locations:
• about 15 ft. downstream of the stoplogs, From around a
boulder on the right sidewali just above the base slab, and
u pwelling through an approximately 1- in, diameter hole in the
base slab next to the sidewall boulder;
• about 22 ft. downstream of the stoplogs, from beneath the end
of the concrete base slab and from the bottom of the right, and
possibly left, sidewall; and
• about 23 ft. downstream of the stoplogs, SA looked through a
void between boulders (marked with orange paint) in the right
sidewall, about waist-height, to observe water flowing roughly
parallel to the culvert behind the side wall through a void,
roughly 1-ft. diameter, between boulders at similar elevation
to the concrete base slab,
2. Scour/erosion of the Primary Spillway culvert bottom (scour hole)
downstream of the end of the concrete slab, This erosion needs to be
addressed during repairs;
3. Ground surface depression on the right side of the gatehouse, a few S,~Lk~
inches deep, roughly circular in plan, about 1 to 2 ft, diameter;
4, Observation well GZ-i(OW) right of the Primary Spillway gatehouse is
missing the well cover and blocked by debris in the well;
5, Uncontrolled seepage at the Auxiliary Spillway; SA observed clear
water discharging on the order of 5 gpm or less from the
embankment toe, about 4 ft. right of the downstream end of the
Auxiliary Spillway, Discharge from the Auxiliary Spillway pipe was on
the order of 2 gpm or less. SA observed no water entering the
upstream end; and
6, Cover of an observation well at the Auxiliary Spillway is broken.Source page 3
These foregoing deficiencies compromise the structural integrity of the dam and
present a potential threat to public safety. ODS has determined that the dam needs
to be repaired, breached or removed in order to bring the dam into compliance with
dam safety regulations.
G.L. c. 253, Sections 44-48 and 302 CMR 10.00 set forth the jurisdiction for ODS
and its authority to take action and order actions to be taken, For your information a
copy of the Dam Safety Regulations, 302 CMR 10,00 Dam Safety, can be found on
the ODS website.
DAM SAFETY ORDER:
In accordance with the authority of G.L, c. 253, Section 47, 302 CMR 10.07
and 10,08 you are hereby ORDERED to comply with the following;
1) Lower the Level of Reservoir Pond: You shall lower the water level of
Reservoir Pond by removing boards in the principle spillway gatehouse to
an elevation not to exceed 142,0, This is the estimated level ecommended
by your engineer. Have your engineer make observations of seepage into
the principle spillway conduit after the reservoir level has stabilized at the
lower level, The lowered level of Reservoir Pond must be achieved by
April 1, 2017
2) Storm Water Runoff Monitoring Plan. You shall develop and
i mplement a Storm Water Runoff Monitoring Plan to ensure that the water
level and problem area are adequately monitored during periods of
significant runoff entering the reservoir, The plan shall be submitted to
ODS For review by April 1, 2017.
3) Conduct Follow-up Inspections: You shall complete follow-up visual
i nspections at six (6)-month intervals, conducted by a registered
professional civil engineer qualified to conduct dam Inspections, at your
cost, until adequate repairs are made or the dam is adequately breached,
ODS notes that the Town recently submitted aFollow-up inspection report
for Reservoir Pond Dam dated January 5, 2017. Therefore, the next
Follow-up inspection is due to be performed on or before July 5, 2017.
Follow-up inspections are to be summary in format and shall provide a
written description, including photographs, of any changes in condition.
Your engineer is to use the attached ODS Poor Condition Dam Follow-up
Inspection Form to report follow-up inspection findings, The form is also
available electronically on the ODS web site. Your engineer shall include a
cover letter on engineering firm letterhead that briefly summarizes the
current follow-up inspection and findings including reservoir level at the
time of the inspection and estimated seepage rates into the primary
spillway conduit.
You shall submit one (1) hard copy printed double-sided and one (1)
electronic pdf copy of all completed follow-up visual inspection reports to
ODS within thirty (30) days of the date of Follow-up inspection field work.Source page 4
4) Conduct Field Studies and Engineering Investigations: Have your
engineer conduct the necessary engineering investigations to evaluate and
design repairs to mitigate the uncontrol led seepage into the principle
spillway conduit. Also have your engineer further evaluate the reported
u ncontrolled seepage at the exit of the auxiliary conduit and determine if
repairs at that location are warranted, Complete the engineering
i nvestigations in accordance with the requirements of the Dam Safety
regulations, and provide a design report to be submitted to ODS by
August 31, 2017,
5) Prepare Chapter 253 Permit Documents: Prepare the necessary dam
safety permit documents for the recommended repair plan and submit to
the ODS by December 31, 2017.
6) Bring the dam into compliance and complete all repair, breach or
removal work. W(th your permit application you must provide a
proposed timeline to construct the selected alternative to repair, breach or
remove the dam, The selected alternative must be completed, and the
dam brought into compliance with Dam Safety regulations, by July 31,
2018.
7.) Additional Requirements:
a. You shall Furnish copies of all required submittals listed above via
certified mail.
b, In order to maintain compliance with the Commonwealth's
Wetlands Protection Laws you may have to seek requisite approval
from your local Conservation Commission in accordance with G.L,
c. 131, §40. You are obligated to contact and maintain
communication with the Canton Conservation Commission and any
other local, state or federal permitting agency the ensure
compliance with the Wetlands Protection Act and any other
regulatory requirements,
c. You must inform the following parties about the condition of the ~
dam and your developing plans to bring the dam Into compliance (~~
with dam safety regulations: all abutters of the impoundment
u pstream; property owners within one-half mile downstream of the
Reservoir Pond Dam; Patricia Huckery, District Manager, Northeast
District, Division of Fisheries &Wildlife, 85 Fitchburg Rd, Ayer, MA
01432; Mille Garcia-Serrano, Regional Director, Department of
Environmental Protection, Southeast Region, 20 Riverside Drive,
Lakeville, MA 02347; Canton Board of Selectmen, 801 Washington
St, 2~d Floor, Canton, MA 02021; Joshua Cohen, Canton
Conservation Administrator, 801 Washington St, Canton, MA
02021; Chief Doody, Canton Emergency Management Director, 99
Revere St, Canton, MA 02021.Source page 5
Please be advised that in accordance with G,L, c. 253, § 47,"any person who fails to
comply with the provisions of this chapter or of any order, regulation or requirement
of the department relative to dam safety, shall be fined an amount not to exceed
$5,000 for each offense, to be fixed by the court." Furthermore, each violation shall
be regarded as a separate and distinct offense and, in case of a continuing violation,
each day's continuance thereof shall be deemed to be a separate and distinct
offense,
N othing in this order releases the owner from the requirements of any prior Dam
Safety Order issued for this dam,
In accordance with 302 CMR 10,08, this CERTIFICATE OF NON-COMPLIANCE and
DAM SAFETY ORDER will be recorded at the Registry of Deeds. Issuance of a
Certificate of Compliance following adequate repair or breaching of the dam will be
required to discharge the CERTIFICATE OF NON-COMPLIANCE and DAM SAFETY
ORDER.
Please direct any technical questions, correspondence, or submittals to Emily Caruso,
Department of Conservation and Recreation, Office of Dam Safety, 180 Beaman
Street, West Boylston, MA 01583. Legal questions should be directed to the DCR
Assistant General Counsel, Ariana Johnson, 251 Causeway Street, Suite 600, Boston,
MA 02114. Additional dam safety information can be found at the DCR-ODS
website; I~ttu://www.mass,aov/eea/agencies/dcr/conservation/dam-safety/.
Thank you for your cooperation.
Sincerely,
Leo R
Camm~ss~oner
CC. Senator Walter F. Timilty
Representative William C. Galvin
Canton Board of Selectmen
Chief Doody, Canton Emergency Management Director
Joshua Cohen, Chair, Canton Conservation Commission
Dave Keddell, U.S. Army Corps
Patricia Huckery, Northeast Region District Manager, DFW
Deirdre Buckley, MEPA
Mille Garcia-Serrano, Regional Director, Southeast Region, DEP
Rob Lowell, DCR
William Salomaa, DCR
Ariana Johnson, Esq., DCR
Tim Purinton, DERSource page 6
Commonwealth of Massachusetts
Department of Conservation and Recreation
Office of Dam Safety Poor Condition Dam Follow-up Inspection Form.
(Complete this inspection form and provide a cover letter on consulting fii~rn letterhead that briefly
summarizes the cu17•ent follow-up inspection and findings. The cover letter shall be signed and stamped by
the Registered Professional Engineer in charge of the inspection)
Dam Name:
Dam Owner:
Nat. ID Number:
Hazard Potential:
Location of Dam (town).
Coordinate location (lat, long).:
Date of Inspection:
Weather:
Consultant Inspector(s): firm name and name of Registered Professional Engineer
in charge of inspection.
Others in Attendance at Field Inspection: include list of names, affiliation and
phone numbers.
Attachments: Updated site sketch with photo locations, Updated photos, and
copy of locus map from Phase 1 report and other applicable
attachments.
I. Previous Inspection date/Overall Condition:
• Date of most recent formal Phase I Inspection Report:
• List the overall condition reported in most recent Phase I Inspection
Report:
II. Previous Inspection Deficiencies:
• List identified deficiencies in the most recent Phase I Inspection Repot~t:
III. Overall Condition of Dam at the Time of the Current Follow-up
Inspection:
a. State the current condition
b. Have conditions changed since the previous inspection? Yes or no.
IV. Comparison of Current Conditions to Condition Listed in Previous Phase
Y Inspection Report:
a. Have any of the deficiencies listed in the previous Phase I Inspection
Report worsened?
b. If yes, list the changes.Source page 7
c, Are there any additional deficiencies that have been identified in the
currentinspecfion?
d. If yes, list the deficiencies and describe.
V. Dam Safety Orders:
• List dam safety orders that have been issued to the dam owner
pertaining to this dam.
VI. Maintenance:
I . Indicate if there exists an operation and maintenance plan for the dani.
2. Indicate if it appears the dam is being maintained.
VII. Recommendations:
VIII. Other Comments or Observations:
IX. Updated Site Sketch with Photo Locations:
X. Updated Photos:
XI. Copy of Locus Map from Phase I Report:
XII. Other applicable attachment:Source page 8
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Stephens Associates Certified W/DBE itrMA, ME, NH and VT
ConsuFting Engineers www.stephensengineers.com ,,~
60 Northrup Dr 668 Main Street, Suite 250
l InsighUul, Cost- Structural Brentwood, NH 03833 Wilmington, Ma,o~ss~
saving Solutions
Geotechnical Celebrating
For Buildings and Phone:(603)772-1417 Phone:(978) 988-2115 -f
InfrasWcture Hydrology &Hydraulics Fax:(603) 772-1418 Fax:(978)988-2117 oUerl~ years
March 3, 2017 SA Project No. 052-16-023
Department of Public Works
Town of Canton
801 Washington Street
Canton, MA 02021
Attention: Mr. Mike Trotta
Re: Sub-Amendment 1B for Levee and Darn Engineering Services
Flood Damage Reduction System
Reservoir Pond Dam,National ID No. MA 00166
Canton, Massachusetts
Ladies and gentlemen:
Stephens Associates Consulting Engineers, LLC (SA, we, our, or us) has prepared this Sub-Amendment 1B at
the request of Mr. Mike Trotta, Superintendent of the Department of Public Works for Town of Canton,
Massachusetts, (Town, Client, you, your, etc.) for engineering services related to the Town's Flood Damage
Reduction System, including upstream contributing dams and drainages, under our existing Agreement dated
February 11, 2016, Amendment 1 dated June 24, 2016, and Sub-Amendment lA dated January 24, 2017
(collectively Agreement). This Sub-Amendment 1B is for engineering services for Reservoir Pond Dam. This
Sub-Amendment 1B amends the Agreement to include the additional scope of services and fee described
herein, which will be charged against the General Services Retainer of Amendment 1.
Our Project understanding and background information are presented below, followed by our scope of
services, estimated fee, and terms and conditions.
Project Understanding and Background
Our understanding of the Project is described in our Agreement and is further based on the following:
Our previous services between November 25, 2016 and January 31, 2017 in which we observed the Dam,
performed a MA DCR ODS-mandated Poor Conditions Follow-Up Inspection, and prepared a report
tided,"Dam Evaluation and Repair Concepts," dated January 31, 2017;
Our email and telephone correspondence with Messrs. Trotta, James Donovan, PE, Town Engineer, and/or
Charles Aspinwall, Town Administrator, between January 31, 2017 and present; and
Our meeting with the Town and ODS on February 22, 2017.
Our January 31, 2017 report (referenced above) recommended repairs to Reservoir Pond Dam to mitigate
uncontrolled seepage. We understand that the Town is working to secure funding for evaluation, design,
pernutting and construction of repairs. In the interim, SA has consulted with the Town to respond to requests
from ODS, and the Town has requested that SA begin evaluation of the Dam necessary for input to design of
repairs.Source page 9
Department of Public Works, Town of Canton, MA SA Project No. 052=16-023
RE: Sub-Amendment 1B for Engineering Services March 3, 2017
Flood Damage Reduction System —Reservoir Pond Dam,Canton, MA Pa ge 2 of 4
During our meeting with ODS and the Town on February 22, 2017; ODS provided a draft of a Certificate of
Non-Compliance and Dam Safety Orders(DSO) that will soon be finalized and issued to the Town requiring
the Town to repair the Dam and perform a Poor Condition Follow-Up Inspection on or before July 5, 2017.
Purpose and Scope of Services
The purposes of SA's services are to consult with the Town on engineering issues with Reservoir Pond Dam
and the Town's interactions with ODS and to begin.evaluation of the Dam in preparation for design of repairs.
Our scope of services include the following tasks:
1. MA DCR ODS Meeting and Consultation — At the Town's request, SA attended a meeting on February
22, 2017 between the Town and ODS. ODS requested the meeting to discuss the next steps for Dam
repair and issued the Draft DSO (referenced above) during the meeting. SA consulted with the Town prior
to and following the meeting. SA subsequently reviewed the DSO and provided comments to the Town
on February 24, 2012. We have also consulted with the Town to plan initial engineering services to
evaluate the Dam in anticipation of repairs. This portion of this Task is complete. We anticipate that
Town personnel, whether the DPW, Town Engineer, Town Administrator, Board of Selectmen, etc., may
have additional engineering-related questions as they and others strive to understand the issues and repair
alternatives for Reservoir Pond Dam. SA will attend an additional meeting, in person or via conference
call at the Town's request.
2. Temporary Cofferdam Evaluation, Design, and Consultation —During the meeting between the Town,
ODS and SA, ODS suggested that the Town evaluate means to reduce risks from storm-induced
impoundment rises, such as by placing super sacks or other temporary cofferdam. SA will evaluate
practicability of a super sack, or similar, temporary cofferdam, review results with the Town, and, if
judged practicable, design the cofferdam and prepare'sketches for the Town's use in constructing the
cofferdam. SA will observe the cofferdam following the Town's construction. SA will prepare a brief
letter documenting the temporary cofferdam and submit to ODS on the Town's behalf.
Planning, Coordination, Site Reconnaissance and Data Gathering, and Base Plan — SA has consulted with
the Town and preliminary planned our services described herein. We have sought out pretzious survey
performed by Rayner/Swanson, Inc. and coordinated with them for the Town to obtain that survey in
AutoCAD format for SA's use as base plan in design of repairs. We have coordinated with the Canton
Conservation Agent who determined that no new wetland delineation is needed, and who provided recent
wetland delineation that was performed on the western (downstream) side of the Dam,
We will reconnoiter the Dam and immediate vicuury to review the existing conditions and configuration in
comparison to previous data, observe deficiencies that may require repair/reconstruction, and obtain
additional information/measurements as we anticipate may be needed for subsequent analysis (e.g.
elevations for hydraulic analyses, etc). Our reconnaissance will be based on visual observation, tape and
level measurements and photographs of readily-visible features and deficiencies. We will perform limited
elevation survey by engineer's level, as we judge necessary, to refine input (i.e. elevations} to our
hydraulic model at key locations. SA will use the results of our observations to guide our design, but, to
economize, will not prepare a report and/or checklist as these are not required by ODS at this time.
Stephens Associates
Consulting Engineers
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Department of Public Works, Town of Canton, MA SA Project No. 052-16-023
RE: Sub-Amendment 1B for Engineering Services March 3, 2017
Flood Damage Reduction System —Reservoir Pond Dam., Canton, MA Page 3 of4
SA will create a base plan for our evaluation and future -design using the survey provided by
Hayner/Swanson, Inc., supplemented by our limited elevation survey and measurements and observations
obtained under this task, and incorporaring the wetland delineation provided by the Canton Conservation
Agent. SA will show approximate property boundaries obtained from the Canton GIS website. Our
services expressly exclude boundary survey..
4. Hydrologic and Hydraulic(H&H)Evaluation —The flood resulting from the 500-year storm is the design
flood for Significant Hazard dams in Massachusetts. Previous H&H evaluation performed by others used
an outdated precipitation for the 500-year storm. 5A will model the drainage area upstream of the Dam
and runoff using the MRCS TR-20 method as implemented by HydroCAD~ or similar computer software
to evaluate flows and water elevations at the e~sting Dam for the 100- and 500-year 24-hour
precipitations predicted by and obtained from the NOAA Northeast Regional Climate Center(NRCC). To
save the Town money and time, SA will use data presented in the previous documents listed in our January
31, 2017 report for input to our model (e.g. impoundment volume, drainage area soil types, etc.), spot-
checking data as we judge appropriate, rather than generating new data at higher cost. The purpose of the
model is to evaluate discharge and impoundment elevations in the design flood. As part of our evaluation,
SA will also consider potential impoundment elevations for Dam operation such that the Dam could pass
the design flood without overtopping. SA will present results of H&H evaluation to the Town via
telephone or in-person meeting. We anticipating summarizing the H&H results in a written Final Design
Report to be prepared as part of permitting in a later phase under future agreement or amendment,.and, as
such, we will not prepare a written report under this Sub-Amendment.
5. MA DCR ODS Follow-Up Inspection — SA will perform a visual Follow-Up Inspection to meet the DSO
requirement for FUI on ar before July 5, 2017. We prepared a brief report in accordance with the Dam
Safety Order, using the ODS Poor and Unsafe Condition Dam Follow-Up Inspection Form required by
ODS, and submitted the FUI Report to ODS on the Town's behalf.
SA's scope of services does not include an environmental assessment or evaluation of any kind, including but
not limited to assessments or evaluations for the presence or absence of wetlands or hazardous or toxic
materials or organisms (e.g., fungi, flora, fauna, bacterial, viruses, etc.) in the soil, surface water, groundwater,
or air, on or below or around this Site. Any observations of odors, colors, or unusual or suspicious items or
conditions made by SA are incidental to our services, and any statements regarding such observations are
strictly for the information of the Client.
Fee
SA will perform the Scope of Services described above on a time and expenses basis to be charged against the
General Services Retainer of Amendment 1 to our existing Agreement. We estimate a fee of $25,000 for the
services described above. The attached Table 1 provides details and basis for our fees. We will shift
hours/dollars between personnel and tasks as needed to perform our services while remaining within the total
cost shown for the aggregate scope of services. SA will not perform services outside of the scope of services
described herein without Client's authorization. If additional services are authorized, SA will perform those
services on a time and expenses basis in accordance with standard rates, as listed below. SA Site visits and
meetings will include mileage and travel time. SA's standard rates are as follows:
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Department of Public Works, Town of Canton, MA SA Project No. 052-16-023
RE: Sub-Amendment 1B for Engineering Services March 3, 2017
Flood Damage Reduction System —Reservoir Pond Dam,Canton, MA Pa~e 4 of 4
DraftsmanlAdministration/Fi~ld Technician $98/hr
Staff and Standard Field Engineering $110/hr
Project Engineering. $125/hr
Project Manager and Senior Engineering $142/hr
Senior Review and Principal Engineering $188/hr
Mileage (per 1RS) $0.535/mile
Direct Costs/Expenses Cost plus 10 percent
Terms and Conditions
SA will perform its services in accardance with the terms and conditions of our existing Agreement. This
Sub-Amendment amends our Agreement to include the additional scope of services and fee described herein.
You can accept this Sub-Amendment by signing and returning one complete original. The signed Sub-
Amendment will form our Agreement for these services, and retaining it to us will notify us to commence the
work. If unauthorized within 30 days of the date of issuance, this Sub-Amendment will be considered null and
void.
We trust that this Sub-Amendment is sufficient to meet your current needs. If you have any quesrions, or
require clarification, please contact us at(978)988-2115 or the email addresses below.
Sincerely,
Stephens Associates Consulting Engineers,LLC
Q
James E. Turner,PE Robert S. Stephens, PE
Project Manager Principal Engineer
JETurner@StephensEngineers.com RSStephens@StephensEngineers.com
JET/RSS:tgbg
Attachments: Table 1 —Fee Estimate
AGREED TO THIS DAY OF , 2017.
SIGNATURE:
NAME:
TTIT.E;
ORGANIZATION:
Stephens Associates
Consulting Engineers
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Geotechnical
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Project: Number: 052-16-023A Sheet 1 of 1
Name: Reservoir Pond Dam, National ID MA00166
Original Work: Canton, Massachusetts
By: J. Turner Date: March 3, 2017 Subject: Sub-Amendment 1 B
'
~ Checked By: RSS Date: March 3, 2017 Table 1 -Fee Estimate
TASK UNIT RATE UNIT QUANTITY TOTAL
($) C$)
1. MA DCR ODS Meeting and Consultation
Principal Engineer $188.00 hour 10 $1,880.00
Project Manager $142.00 hour 14 $1,988.00
Staff Engineer $110.00 hour 0 $0.00
Mileage $0.54 mile 200 $108.00
2. Temporary Cofferdam Evaluation, Design and Consultation
Principal Engineer $188.00 hour 8 $1,504.00
Project Manager $142.00 hour 12 $1,704.00
Staff Engineer $110.00 hour 4 $440.00
Drafting/Administration $98.00 hour 2 $196.00
Mileage $0.54 mile 100 $54.00
3. Planning, Coordination, Site Reconnaissance and Data Gathering, and Base Plan
Principal Engineer $188.00 hour 12 $2,256.00
Project Manager $142.00 hour 18 $2,556.00
Staff Engineer $110.00 hour 12 $1,320.00
Drafting/Administration $98.00 hour 8 $784.00
Mileage $0.54 mile 100 $53.50
4. Hydrologic and Hydraulic Evaluation
Principal Engineer $188.00 hour 8 $1,504.00
P roject Manager $142.00 hour 15 $2,130.00
Staff Engineer $110.00 hour 30 $3,300.00
Drafting/Administration $98.00 hour 4 $392.00
Mileage $0.54 mile 0 $0.00
5. MA DCR ODS Poor Condition Follow-Up Inspection, July 2017
Principal Engineer $188.00 hour 5 $940.00
Project Manager $142.00 hour 10 $1,420.00
Staff Engineer $110.00 hour 2 $220.00
Drafting/Administration $98.00 hour 2 $196.00
Mileage $0.54 mile 100 $54.00
ESTIMATED TOTAL: $25,000
Copyright OO 2017 Stephens Associates Consulting Engineers LLC
Stephens ASSOCIates
R@VISIOIIS: Cunwlting Engineers
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By: Date: aroma, ~~;~
By: Date: w+~,. Hr~~sr & Hrdraulics
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Stephens Qssociafes
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Certified W/DBE in MA, ME, NH and VT
www.steohensengineers.cbm
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60 Northrup Dr 668 Main Street, Suite 250
Insightlul, Cosh Structural Brentwood, NH 03833 Wilmington, MA 01887
saving soluhor~s
Geotechnical Celebrating
(or Buildings and Phone:(603) 772-1417 Phone:(978) 988-2115
In6asWGure Hydrology &Hydraulics Fax:(603)772-1418 Fax:(978)988-2117 over~~ years
March 3, 2017 SA Proposal No. 17-004
Department- of Public Works
Town of Canton
801 Washington Street
Canton, MA 02021
Attention: Mr. Mike Trotta
Re: Proposal for Dam Engineering Services
Reservoir Pond Dam,
National ID No. MA 00166
Canton, Massachusetts
Ladies and gentlemen:
Stephens Associates Consulting Engineers, LLC (SA, we, our, or us) has prepared this Proposal at the request
of Messrs. Mike Trotta, Superintendent of the Department of Public Works and Charles Aspinwall, Town
P,dministrator for Town of Canton, Massachusetts,(Town, Owner, Client, you, your, etc.) for evaluation and
preliminary design of repairs to Reservoir Pond Dam (Dam, Project, etc.).
Our Project understanding and background information are presented below, followed by our scope of
services, estimated fee, and terms and conditions.
Project Understanding and Background
Our understanding of the Project, as presented herein, is based on the following:
Our previous services between November 25, 2016 and January 31, 2017 in which we observed the
Dam, performed a MA DCR ODS-mandated Poor Conditions Follow-Up Inspection, reviewed
previous documents prepared by others, conceptualized repairs, and prepared a report tided, "Dam
Evaluation and Repair Concepts," daeed January 31, 2017;
Our email and telephone correspondence with Messrs. Trotta and Aspinwall between January 31,
2017 and present; and
Our meeting with the Town and ODS on February 22, 2017.
Figure 1 —Site Location map and Figure 2 —Site Aerial Photograph show the location of Reservoir Pond Dam
(Site) on Pleasant Street in Canton, MA. The Dam discharges through a stoplog-controlled primary spillway
and an auxiliary (emergency) spillway. The Dam is classified as Large Size, Significant Hazard by ODS.
In January 2017, SA performed a Poor Condition Follow-up Inspection (FUI) mandated by the Massachusetts
Deparnnent of Conservation and Recreation, Office of Dam Safety (ODS) by Dam Safety Orders (DSO) in
which we observed uncontrolled seepage at the primary and auxiliary spillways. SA subsequently evaluated
the Dam through review of documents provided by the Town that described engineering evaluation, design,Source page 14
Department of Public Works, Town of Canton, MA 5A Proposal No. 17-004
RE:Proposal for Dam Engineering Services March 3, 2017
Reservoir Pond Dam, National ID No. MA00166, Canton, MA Pa~e 2 of 5
and construction of repairs by others between 2009 and 2016. Specifically, Canton Developrrient Properties,
LLC (CDP)(or similar enxityl)constructed repairs in 2012 and 2016 that consisted, generally, of removing
vegetation, installing sheet piles and low permeability fill along portions of the upstream face, and limited
repairs to the primary and auxiliary spillways.
In our January 31, 2017 report, separate from our FUI report, SA conceptualized new -repairs to mitigate
seepage and preliminarily estimated costs for design, permitting and construction. We understand that the
Town is considering Alternatives A and B in that report. Alternative A included repairing the Dam and
spillways. Alternative B included repairing the Dam and replacing the spillway outlet structures with repair of
remaining portions of the spillways. The Town bas requested that SA perform inirial engineering to evaluate
the Dam, advance the two repair alternatives beyond conceptual to preliminary design, and to refine the
preliminary cost estimates.
Purpose and Scope of Services
The purposes of SA's services are to evaluate the Dam and advance the two repair concepts (Alternatives A
and B) identified in our January 31, 2017 report, listed above, through preliminary design and to refine the
estimates of cost to be used by the Town to select a single alternative for design development, final design and
construction. Our scope of services includes the following tasks:
1) Subsurface Explorations and Geotechnical Laboratory Testing — SA will engage a drilling subcontractor
(Driller) to perform one day of geotechnical subsurface ex loration; on Pleasant Street. We anticipate
completing up to 2 borings to ep sup to 40 feet below ound surfa ~e (bgs) per boring. The purposes of
the borings are to o twin subsurface information to supplement previ pus published information for use in
our subsequent evaluation and design. Prior to performing the borings, SA will review geologic
information readily available online and in our files for geologic conditions at the Dam and immediate
viciuiry.
SA will mark the borings in the field prior to drilling, and will notify DigSafe System, Inc. for utility
clearance, as required by law. SA will provide a field engineer at the site, full time, during the borings to
coordinate and observe the drilling, to collect and eotechnicall classify the soil and rock samples, and to
log e exp orations. The er will obtain a street opening permit from the Town of Canton if nee ed,
w c ewe assume the Town will issue at no cost to the Driller/SA. The Driller will provide traffic
controls such as cones to delineate the work area. We assume drilling will occur dunng week=day work
hours etween am an pm and that the Town will provide a police detail at no cost to SA/Driller.
The Driller will advance the borings using hollow-stem auger, cased wash-boring (aka, drive and wash)
andlor open-hole or other drilling techniques, at the sole discretion of SA based on budgeting, Project
goals, drilling progress, and types of strata encountered in the borings, etc. The Drillers will perform
standard penetration tests (SPT) and attempt to obtain split-spoon samples continuousl or at about 5-foot
intervals an at c anges m strata perceived by e ers, or as requested by 5A field personnel. If the
D er encounters refusal above the planned or anticipated boring termination depth, then at the sole
1 We understand that the names of the entity(s) owning/repairing the Dam since 2009 for transfer of ownership to the
Town of Canton, may have included Canton Development Properties, LLC, Canton Holdings, LLC, Napleton Aire, LLC,
and/or KRN Aire Trust. Where this Letter refers to CDP,the reference is collectively to these entities that may have
owned the Dam at that time.
Stephens Associates
Consulting Engineers
r.~ymd.caF Structural
~ Geotechnical
mr~:~ Hydrology &HydraulicsSource page 15
Department of Public Works, Town of Canton, MA SA Proposal No. 17-004
RE: Proposal for Dam Engineering Services March 3,2017
Reservoir Pond Dam,National ID No. MA00166, Canton, MA ~ Pa ~e 3 of 5
discretion of 5A based on depth of refusal, soil types, drilling progress, etc., SA may request that.the
Driller core rock to confirm the presence of bedrock, visually evaluate its characteristics, and collect
samples of the rock core. At the end~of drilling, the Drillers will construct groundwater observation wells
in the borings or bacl~ill the orings wi cement-bentonite out, at SA's scretion. The purpose of the
we s is to monitor groun water level in the embankment. The Drillers will discard excess cuttings to the
ground surface off the road shoulder near the boring locations. Actual boring/sampling depths and total
drilling production will be based on budgeted time, conditions encountered and drilling factors subject to
the sole discretion of SA considering the nature, depth and rate of progress of drilling and Project goals.
We will perform, or engage a geotechnical testing laboratory to perform, grain size analyses (sieve or sieve
and hydrometer) on up to 6 samples obtained from the borings. The purpose of the testing is to assist in
soil classification and evaluarion of particle size distribution for our estimation of soil permeability and
other properties.
2) Seepage Evaluation — SA will evaluate seepage through the Dam for design of repairs. We will select
representarive cross-secc~on(s), interpret piezometric surface and material properties for those cross-
sections, and evaluate seepage potential, internal erosion potential and piping potential to assist us in
design of repairs. SA will interpret groundwater elevations based on previously published data from the
existing groundwater observation wells and data gathered from our subsurface explorations.
3) Alternatives Concept Design and Cost Estimate — SA will use the results of the above tasks to
preliminarily design two repair alternatives and refine our cost estimate for design, pernutting and
construction.Est estimate w e ased on readily-available cost data such as that published by RS
MeansancTDepartments of Transportation in Massachusetts, New Hampshire and Connecticut, and our
~ and the Town's recent, previous experience and/or contacts with contractors.
To save money and time, 5A will present the results of the evaluation, concepts and cost estimate to the
Town via a brief email fo owe y a co erence call or meeting to discuss, but we will not prepare a
wiled written report of our evaluation at this time. If requested by the Town, 5A will prepaze a very
bnef letter summarizing the concepts and cost estimate. We anticipate that we will present results of
seepage analyses, subsurface explorations and geotechnical laboratory testing in a Final Design Report, as
needed to support an ODS Chapter 253 Permit Application, to be prepared as part of permitting in a later
phase under future amendment.
To save the Town money and time, 5A will use data generated by_CDP's engineer described in the documents
listed in our January 31, 2017 report, rather than regenerating the data ourselves at greater expense and time.
Furthermore, our services in this Proposal exclude evaluation of the Dam's hazard classification (by dam
breach analysis) and slope stability. CDP's engineer evaluated the hazard classification (which was apparently
accepted by ODS) and slope stability, concluding that the upstream and downstream slopes are stable
according to ODS criteria. If requested by the Town to re-evaluate these aspects, SA could perform such
evaluation under amendment for additional fees.
Stephens Associates
Consulting Engineers
o-~yn~v cm- Struciur2l
'~"ig5oki6oiB
M cgs mw Geotechnical
rra:e,~ Hydrology8 HydraulicsSource page 16
Department of Public Works, Town of Canton, MA SA Proposal No. 17-004
RE: Proposal for Dam Engineering Services March 3,2017
Reservoir Pond Dam,National ID No. MA00166, Canton, MA Page 4 of5
l
After completion of the tasks described herein, we anticipate that the Town will select an alternative for design
by SA under a future amendment. Additional engineering services (not included in this Proposal) will be
needed to complete design development, final. design, permitting, and bid and construction phases. Our cost
estimate prepared under Task 3 will include the costs for these services.
Additional Assumptions
In addition to the factors and assumptions indicated above, we have assumed the following:
• The Dam is classified as Significant Hazard by ODS. If ODS later determines the Dam to be High
Hazard, or requires review of hazard classification, additional services beyond the scope of those
herein, and corresponding fees, would be needed,
• The drilling locations are accessible by truck-mounted drilling equipment, and are otherwise
unrestricted by regulations regarding the performance of our services. If permits are required for
borings, such permits would need to be applied for by SA for additional fee under amendment to this
Agreement.
• Our and the Drilling Contractor's e~sting insurance coverages are adequate.
• The borings will be performed with equipment that will disturb the ground surface and vegetation
(trees, bushes, brush, etc.). SA will not be required to restore the ground surface or vegetation (e.g.
landscaping, grading, placing hay, plantings, etc.). If ground surface or vegetation restoration is
required, we will incur additional time and expenses and will require additional fee to cover all our
costs plus markup on these direct expenses.
• The Site is not contaminated, and SA will not be required to take special precautions or measures
regarding exposure.to, or handling of, environmental contaminants during field explorations (borings).
If we observe evidence of contamination, we will halt the drilling and notify the Town. The boring
spoils (e.g., soil cuttings and wash mud, etc.) will be the property of the Town. When each boring is
complete the drillers would bacl~ill the borehole with bentonite and/or cement grout, and drum the
drilling spoils for disposal by the Owner or by SA for additional fee under amendment to this
Agreement.
• SA's scope of services does not include an environmental assessment ar evaluation of any kind,
including but not limited to assessments or evaluations for. the presence or absence of wetlands or
hazardous or to~c materials or organisms (e.g., fungi, flora, fauna, microarganisms, etc.) in the soil,
surface water, groundwater, or air, on or below or around this Site. Any observations of odors, colors,
or unusual or suspicious items or conditions made by SA are incidental to our services, and any
statements regarding such observations are stricfly for the information of the Client.
Fee
SA will perform our Scope of Services in accordance with the terms and conditions of this Proposal for a lump
sum of $20,000. The attached Table 1 provides basis for our fee. We will shift -hours/dollars between
personnel and tasks listed in Table 1 as needed to perform our services while remaining within the total fee
shown for the aggregate scope of services. SA will not perform services outside of the scope of services
described herein without Client's authorization. If additional services are authorized, SA -will perform those
services on a time and expenses basis in accordance with standard rates, as listed below. SA Site visits and
meetings will include mileage and travel time. SA's standard rates are as follows:
Stephens Associates
Consulting Engineers
wymu.c~- Shuctural
'^i'9~"~1°
creasy:tee Geotechnical
nr~ne~. Hydrology ~ HydraulicsSource page 17
Depamnent of Public Works, Town of Canton, MA SA Proposal No. 17-004
RE: Proposal for Dam Engineering Services March 3, 2017
Reservoir Pond Dam, National ID No. MA00166, Canton, MA Page 5 of 5
Draftsman/Administration/Field Technician $98/hr
Staff and Standard Field Engineering $110/hr
Project Engineering $125/hr
Project Manager and Senior Engineering $142/hr
Senior Review and Principal Engineering $188/hr
Mileage(per IRS) $0.535/mile
Direct Costs/Expenses Cost plus 10 percent
Terms and Conditions
SA will perform its services in accordance with this Proposal, including SA's General Conditions for
Engineering Services attached as E~ibit A. You can accept this Proposal by signing and retaining one
complete original. The original, signed Proposal will form our Agreement for these services, and returning it
to us will notify us to commence our services. If unauthorized within 30 days of the date of this Proposal, this
Proposal will be considered null and void.
This agreement is effective as of February 27, 2017. We trust that this Proposal is sufficient to meet your
current needs. If you have any questions, or require clarification, please call us.
Sincerely,
Stephens Associates Consulting Engineers, LLC
a~
James E. Turner, PE Robert S. Stephens, PE
Project Manager Principal Engineer
RSS/JET:tgbg
Attachment: E~ibit A —General Conditions for Engineering Services
Figure 1 —Site Location Map
Figure 2 —Aerial Photograph
Table 1 —Fee Estimate
AGREED TO THIS DAY OF , 2017.
SIGNATURE:
NAME:
TTIT.,E:
ORGANIZATION:
Stephens Associates
Consultlng Engineers
n~,~n.c~ Shuctural
=""gSohi60f°
~ ~u~ys am Geotechnical
•w~~e~,m,~ Hydrology &HydraulicsSource page 18
EXHIBIT A -GENERAL CONDITIONS FOR ENGINEERING SERVICES
1. PART1Es:"SA" means Stephens Associates Consulting Engineers,LLC and its successors and assigns. "Client" means addressee on this proposal and its
successors or assigns. Qient and SA will be jointly referred to as "we," or '~s." "Owner" means the developer, public entity, or Project Site proprietor,
and its successors and assigns, that uses the work performed by,the Client or SA, or that owns or manages any constructed facility built using the work
products prepaied by, or recommendations provided by,SA under taus Agreement, at the time SA's Services are undertaken. Client may be Owner.
2. SExvICES: SA will provide [he Services described in its Proposal in accordance with the standard of care of engineers providing similar services under
similaz conditions. SA does not warrant or guarantee its Services. SA deliverables, including all attachments thereto, will be provided solely in
electronic (portable document format or .pdfl file and/or hazdcopy. Deliverables include letters, memoranda, reports and designs, and any and all
attachments thereto in support/illustration. All electronic%omputer models and calculations created or modified by SA in execution of services and
preparation of deliverables, including but not limited to spreadsheets and CAD files, shall be the sole property of SA.
3. PAYtv~NT: Client will pay SA's invoices within 10 days of receipt. Client will also pay a late payment charge at the rate of 1.5%per month, or portion
thereof, after the date of invoice for each and every amount unpaid. At SA's option, SA may suspend or terminate this Agreement if payments are not
made when due. Unless otherwise agreed in writing, SA's Services are billed on atime-and-materials basis using SA's Fees Schedule. Limitations on
the amount to be billed are estimates only, and are not an agreement by SA that SA's Services will be completed for the estimated amount.
4. SUssUxFnCE CoNDiT~oNs: Client will provide SA with all information Client bas, or can reasonably obtain, concerning the Project, including
subsurface conditions and the location of subsurface or hidden pipes, utilities or structures. SA will attempt to avoid damage to subsurface s~uctures,
and will take reasonable precautions to avoid damage to underground structures, but SA is not responsible for any damage to subsurface pipes, utilities
or structures that Client or others have not disclosed to SA.
5. ENVIItONMENTAL CONTAMINATION AND HAZA1tI)oUs MATERIAL: SA will not investigate, treat, transport or dispose or arrange for transport, treatment
or disposal of environmental contamination or hazardous material, except as expressly stated otherwise herein or by mutually authorized amendment to
this Agreement. If environmental contamination or hazardous material is discovered at the Project Site, SA can terminate SA's obligations under this
Agreement.
6. LmzrrazzoN of REMEn~s: This Agreement will be enforced solely under Massachusetts Law. SA's liability and the liability of SA's employees and/or
subcontractors, to Client and any third parties affected by SA's work, for damages arising from Services or from this Agreement is limited to SA's fees
received under this Agreement or the extent of available coverage of SA's insurance, whichever is less. Such limit of liability will include any and all
attorney's fees. Neither SA nor Client will be liable for consequential damages incurred by either of us.
7. INsuitANCE: SA will maintain claims made professional liability, general liability, and automobile liability insurances. Client has, or will purchase,
insurance sufficient to protect Clients insurable interests in the Project, including but not limited to property ownership. We waive any claims against
each other for interests covered, or that should have been covered by insurance required by this pazagraph,including subrogated claims.
8. SITE SAFETY: Except for SA's employees, SA assumes no responsibility for the safety of anyone on Site before, during-or after SA's presence a[ the
Site.
9. MATERIAL SAMPLES: SA shall preserve such soil, rock, water, or other samples obtained from the Project Site as it deems necessary for the Project, but
for not longer than forty-five (45) days after issuance of any documents that include the data obtained from these samples. SA shall not be responsible
( for the removal and ]awful disposal of samples, cuttings and hazardous substances, unless other arrangements aze mutaally agreed in writing. SA shall
not be responsible for or take custody of monitoring wells and probes installed during any services by SA. Such responsibilities are typically the
Owner's, unless otherwise agreed in writing. Client shall notify Owner of this responsibility and take any and all necessary steps for sample possession
or disposal, and for proper maintenance,repair or closure of wells or probes.
10. RELATIONsffiP of 'rte,PARTIES: SA shall perform Services under this Agreement as an independent conh~actor, and its employees shall at all times be
under its sole discretion and conffol. SA shall select the means, manner and method of completing Services without detail, conh~ol, or direction from
Client.
11. 1VIEniaTTON: Prior to any litigation, arbitration or other proceeding, we will attempt to mediate any dispute between us. The American Arbitration
Association will conduct the mediation, unless we otherwise agree. We will share all fees and costs of the mediation equally.
12. 1~tn PARTY RELIANCE: All Documents are prepared, and services performed, solely for use by Client for application to the specific Project, and shall
not be provided to any other person or entity without SA's written consent, nor shall they be mentioned, communicated, disclosed or referred to in any
offering circular, securities offering, loan application, real estate sales documentation, or similar promotional material, without SA's express written
authorization. Client agrees to defend, indemnify and hold SA harmless from and against any action or proceeding brought by any person or entity
claiming to rely upon information or opinions contained in documents prepared by us, or on other documents provided to such person or entity, that are
published, disclosed or referred to without SA's written consent. No party other than Client may rely, and Client shall make no representations to any
party that such party may rely, on Documents without SA's express written authorization.
13. T~RM~NATION: Either of us may terminate this Agreement for convenience by giving fourteen (14) days written notice. Either of us may terminate this
Agreement for cause by giving seven (7) days written notice, except that SA may terminate at any time, and without advance notice, for lack of payment
when due. If this Agreement is terminated by Client, Client shall pay SA,in addition to any other compensation due under ttris Agreement, any amount
incurred by SA in performing Services, in preparing to perform Services, and in orderly terminating Services.
14. RiGaT.To RELY: Client will provide, or will arrange for others to provide through Client, such e~cisting project and site information as necessary or
requested by SA, including existing conditions surveys, topographic surveys, preliminary structure layouddesign, structure loads, previous subsurface
explorations, etc. SA's Services may also include review of information SA.ibtains from other sources. SA may use, and may reasonably rely on, all -
such information in the performance of its Services under this Agreement.
15. R~esT of ENTRY: Client understands, and has informed Owner, that subsurface explorations (soiUrock borings and test pit excavations) and other work
performed as part of SA's Services may unavoidably alter conditions or affect [he surface and subsurface environments at the Project Site. SA will
operate with reasonable care to limit damage to the Project Site. Unless otherwise agreed to in writing, the cost of repairing such damage will be borne
by others. Client is authorized to grant, and hereby grants, SA right-of-entry to perform any and all measures necessary to accomplish SA's Services at
the Site for the subject Project.
16. CoN7'nvilnvG AGRFR~rxN'r; If SA provides services to Client, but which the parties do not confirm through execution of an amendment to this
Agreement, the obligations of the parties to indenu~ify and the limitations on liability established under this Agreement shall apply to such services as if
an amendment had been executed by the parties. The indemnity obligations and the limitarions of liability established under this Agreement shall
~ survive the expiration or termination of this Agreement.
17. ~1LL ANn FIlVAL AGREEMENT: This Agreement is the full and final agreement between us, supersedes any prior agreements, and may not be modified
except by a writing executed by both of us.Source page 19
Project: Number: 17-004 Sheet 1 of 1
Name: Reservoir Pond Dam Repairs, ID No. MA00166
Original Work: Canton, Massachusetts
- By: J. Turner Date: March 3, 2017 Subject: FIGURE 1 -Site Location Map
.Checked By: Date:
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Map created with TOPO!~ 02001 National Geog~phic (w~~rv.netionslgeographic.com/topo}
Copyright OO 2017 Stephens Associates Consulting Engineers LLC StBphenS ASSOCIates
C~ns~ilting Fiigneers
R@VISIOIIS:
By: Date: ~~ sw~wr~
~~~,~ Hydrologyc~ia~n~~~
By: Date: ~.~. &Hydraulics
s~cEoai ~~. i~ i/oo www.stephensengineers.com 668 Main Street, Wilmington, MA 01887 (978) 988-2115Source page 20
Project: Number: 17-004 Sheet 1 of 1
Name: Reservoir Pond Dam Repairs,. ID No. MA00166
Original Work: Canton, Massachusetts
By: J. Turner Date: March 3, 2017 Subject: FIGURE 2 -Site Aerial Photograph
Checked By: Date:
Approximate
Auxiliary Spillv~ay
Reservoir Pond Dam
Approximate Primary
Spillway
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tia St
Scale = 1:1,1 ~S
~
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Image obtained from MassGIS, which indicates photograph taken on May 11, 2016, North
and obtained by MassGIS from Google. http://maps.massgis.state.ma.us/map_ol/oliver.php
accessed January 11, 2017
Copyright02017 Stephens Associates Consulting Engineers LLC Stephens Associates
R@VISIOIIS: Cortsuking Engineers
By: Date: may~cF StrucWral
,.;,,~. c~~~,,,;~,
By Date: Hydrdo~ydHydrauiics
s~cEoai ~~. i~ i/oo www.stephensengineers.com 668 Main Street, Wilmington, MA 01887 (978) 988-2115Source page 21
Project: Number: 17-004 Sheet 1 of 1
Name: Reservoir Pond Dam Repairs, ID No. MA00166
Original Work: Canton, Massachusetts
By: J. Turner Date: March 3, 2017 Subject: Table 1 -Fee Estimate
Checked By: RSS Date: March 3, 2017
TASK UNIT RATE ($) UNIT QUANTITY TOTAL ($)
1. Subsurface Explorations and Geotechnical Laboratory Testing
Principal Engineer $188.00 hour 2 $376:00
Project Manager $142.00 hour 4 $568.00
Staff Engineer $110.00 hour 16 $1,760.00
Drafting/Administration $98.00 hour 0 $0.00
Mileage $0.54 mile 100 $53.50
Driller
Mob/demob $125.00 per hour 3.5 $437.50
Drill rig with two-man crew $1,500.00 Day 1 $1,500.00
Rock drilling and coring $22.00 ft 5 $110.00
Overtime $245.00 hour 0 $0.00
Grout boreholes $5.25 ft 80 $420.00
2" PVC groundwater observation wells $11.50 ft. 30 $345.00
Locking road box well cover $70.00 ft. 2 $140.00
Geotechnical Lab Testing (Sieve) $95.00 each 0 $0.00
Geotechnical Lab Testing (Sieve &Hydrometer) $150.00 each 6 $900.00
Mark-up on direct expenses $3,852.50 Percent 10% $385.25
2. Seepage Evaluation
Principal Engineer $188.00 hour 6 $1,128.00
Project Manager $142.00 hour 12 $1,704.00
Staff Engineer $110.00 hour 32 $3,520.00
Drafting/Administration $98.00 hour 2 $196.00
Mileage $0.54 mile 0 $0.00
3. Alternatives Concept Design and Cost Estimate
Principal Engineer $188.00 hour 10 $1,880.00
Project Manager $142.00 hour 18 $2,556.00
Staff Engineer $110.00 hour 16 $1,760.00
Drafting/Administration $98.00 hour 2 $196.00
Mileage $0.54 mile 100 $53.50
Estimated Total $19,989
CopyrightO 2017 Stephens Associates Consulting Engineers LLC Ste[lhens ASSOclates
f~eVISIOIIS: Cunsukiug Enpneers
~ _ By: Date: ~~ c~e~;~
By: Date: ~.~.~ H yd rolSyr 3 Hya~~r~
~r~.~,e~q
s~cEoai ~~. i~ i/oo www.stephensenQineers.com 668 Main Street, Wilmington; MA 01887 (978) 988-2115Source page 22
/Ir~~ la /`~br~ ID
Stephens Associates Certified WIDBE in MA, ME, NH and VT
Consulting Engineers www.stephensengineers.com
60 Northrup Dr 668 Main Street, Suite 250
Insigntful, Cost- Structural Brentwood, NH 03833 Wilmington, MA 01887
saving Solutions
for Buildings and Geotechnical Phone:(603) 772-1417 Phone:(978)988-2115 ASFE'
_ _— —-
Infrastruelure Hydrology &Hydraulics Fax:(603)772-1418 Fax:(978)988-2117
January 31, 2017 SA File 052-16-023A
Town of Canton
Department of Public Works
Town Hall
801 Washington Street
Canton, MA 02021
Attention: Mr. Michael Trotta
Superintendent of the Department of Public Works
Re: Dam Evaluation and Repair Concepts
Reservoir Pond Dam
National ID No. MA00166
Canton, MA
Ladies and gentlemen:
Stephens Associates Consulting Engineers, LLC (SA, we, our or us) has evaluated sinkholes, seepage and
subsurface voids through review of documents, performed Poor Condition Follow-up Inspection,
conceptualized repairs, and estimated repair costs for Reservoir Pond Dam (Dam) located in Canton, MA at
the request of Mr. Michael Trotta, Superintendent of the Department of Public Works, Town of Canton
Massachusetts(Town, Client, you or your). The results of these services are described herein.
The Dam is in "Poor Condition" under ODS prescriptive evaluation criteria because of uncontrolled seepage
and subsurface voids observed by the Town and SA on November 25, 2016 and January 5, 2017. Canton
Development Properties, LLC (CDP)(or similar entity') constructed repairs to the Dam in the summers of
2012 and 2016 under Chapter 253 permits issued by the Massachusetts Department of Conservation and
Recreation, Office of Dam Safety (ODS) and as part of an agreement between the Town and CDP to transfer
their Dam ownership to the Town. It is our understanding that the goals of the 2012 and 2016 repairs were to
repair sinkholes, subsurface voids and uncontrolled seepage through the Dam and into the spillway culverts.
Based on the recently observed, uncontrolled seepage abnear both the primary and auxiliary spillways, it
appears that, while the repairs may have generally addressed the sinkholes, they did not fully address the
uncontrolled seepage causing sinkholes, nor the seepage entering the spillway culverts. The Town therefore
requested that SA review previous documents provided to us to evaluate sinkholes, seepage, and repairs at the
primary and auxiliary spillways, conceive of alternatives to repair the Dam, and estimate costs. Our
evaluation, alternatives concepts, and cost estimates are subject to the limitations described herein.
We understand that the names of the entity(s) owning/repairing the Dam since 2009 for transfer of ownership to the
Town of Canton, may have included Canton Development Properties, LLC, Canton Holdings, LLC, Napleton Aire, LLC,
and/or KRN Aire Trust. Where this Letter refers to CDP,the reference is collectively to these entities that may have
owned the Dam at that time.Source page 23
Town of Canton, Massachusetts SA Project No.052-16-023A
RE: Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam,Canton, MA Page 2 of 14
Summary
We noted four interrelated, general issues affecting the Dam from our document review and recent on-site
observations: uncontrolled seepage, seepage into the primary and auxiliary spillway culverts, subsurface voids,
and sinkholes; though the documents do not often distinguish explicitly between them. Uncontrolled seepage
can cause internal erosion (or "piping") in which flowing water transports (or entrains) material, eroding the
ground, creating voids, "pipes" or channelized flow below ground surface. Uncontrolled seepage can be
through the embankment or can enter the sides or bottoms of the spillways and downstream millraces or
similar structures, in this case culverts. Sinkholes on embankment dams are typically formed by surface
collapse of subsurface voids, and are typically caused by piping/internal erosion. Taken together, internal
erosion and sinkholes are forms of ground loss, and as such, progressive (i.e, worsening) ground loss can lead
to dam breach or failure. In other words, uncontrolled seepage can cause ground loss that jeopardizes dam
safety, and is therefore categorized as a structural deficiency by ODS,resulting in "Poor Condition" rating and
requiring repair. Following a "Poor Condition" rating, ODS typically issues Dam Safety Orders mandating
Poor Condition Follow-Up Inspections at 6-month intervals, indefinite drawdown of the impoundment,
Dam deficiency monitoring, and/or evaluation, design and construction of repairs to improve the condition to
better than "Poor."
Numerous documents identified deficiencies of sinkholes and uncontrolled seepage at both the primary and
auxiliary spillways between 1999 and 2010. CDP's engineer prepared a Phase II Report in 2010
recommending repairs expressly of seepage, subsurface voids and sinkholes at both the primary and auxiliary
spillways. It appears that neither the 2012 design nor 2012 construction fully implemented the
recommendations of the Phase II Report. The 2012 construction also differed significantly fiom the 2011
Chapter 253 Permit Application and 2012 Revised Design Drawings that formed the basis for the Chapter 253
Permit issued by ODS.
Seepage and sinkholes were observed by several parties in 2013 soon after• completion of repairs. ODS
expressed significant concerns regarding uncontrolled seepage between 2013 and 2014, and mandated
auxiliary spillway repair as well as evaluation and repair of primary spillway sinkholes in its 2016 Renewed
Chapter 253 Permit. The 2016 repairs do not appear to have addressed uncontrolled seepage at either the
primary or auxiliary spillways, nor do the repairs appear entirely consistent with the 2016 Renewed Chapter
253 Permit issued by ODS.
Uncontrolled seepage and voids persist around the primary and auxiliary spillways, as evidenced by
observations in November 2016 and January 2017 by the Town and SA, resulting in the current "Poor
Condition" rating mandated by ODS's imposing of a Follow-Up Inspection (FLJI) report and prescribed
assessment criteria. Further details of our document review are described below. Based on our review of
previous documents and our• limited FUI, current deficiencies appear to include:
• UnconU~olled seepage through the embankment around the primary spillway;
~ Uncontrolled seepage into the primary spillway culvert;
• Sinkholes and voids around beneath the primary spillway;
• Scour/erosion at the primary spillway culvert bottom;
• Uncontrolled seepage through the embankment around the auxiliary spillway;
• Uncontrolled seepage into the auxiliary spillway culvert; and
• Potential voids around the auxiliary spillway
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Town of Canton, Massachusetts SA Project No.052-16-023A
RE: Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam,Canton, MA Pale 3 of 14
We recommend that the Town consider• its short- and long-term goals in owning the Dam before selecting and
proceeding with repairs, as the Town's goals likely differ from those of CDP for the previous repairs. Some
possible Town goals might include:
• Improve the Dam's condition to better than "Poor" under ODS prescriptive criteria;
• Reduce sl~ort term financial outlay while keeping the Dam;
~ Reduce risk of dam failure and associated upstream and downstream impacts;
• Reduce future operation, maintenance, and repair costs;
• Maintain a desired normal pool elevation, which may differ from the current operations resulting from
the CDP repairs; and
• Improve discharge capacity such that pond drawdown in advance of storms is not required, as it is
under current operation following CDP repairs.
We conceptualized three alternatives to address current deficiencies listed above, based on potential Town
goals, and estimated concept-level costs, shown in the table below. The alternatives and basis for costs are
further discussed herein and should be read and understood.
Estimated Range of Short-Term Cash Outlay
Alternative (2017 $)for Com arison/Decision-makin 1
Low Avera e Hi h
A: Repair Embankment and Spillways —
Address currentl identified deficiencies $SOOk $600k $750k
B: Repair Embankment, Replace Spillways —
Address currently identified deficiencies, $650k $750k $950k
enhance serviceable life and u grade o eration.
C: Reconstruct Dam —Address identified and
unidentified deficiencies, further enhance $2M $2.SM $3M
serviceable life and u rade o erations
Notes: 1. SA estimated financial costs (i.e. cash outlay) in 2017 dollars. These costs are based on preliminary concepts and are intended
to provide order-of-magnitude costs for comparison. Costs include construction with a 20 percent contingency, and design-, bid- and
construction-phase engineering services. SA estimated costs using unit costs published by MassDOT, as well as our judgment and
experience on previous projects. Note that average cash outlay is based on average unit rates for the concept components and is not the
average of total low and high cash outlay estimates. We recommend using the average costs for evaluation, comparison between
alternatives and decision-making, however, we recommend using the high costs for budgeting once an alternative is selected.
Estimated cost for a selected alternative can be refined during design development and final design.
We conceptualized each of the alternatives to improve the Dam's condition above "Poor." If the Town's goals
include reducing short term financial outlay while keeping the Dam and reducing risks, the Town may
consider Alternative A. If the Town's goals include reducing risks, reducing future operation, maintenance
and repair costs, and considering improvements, we recommend Alternative B. We recommend Alternative C
if the Town's goals are to reduce risks and costs and improve operations to the extent practicable, in exchange
for higher short term cost. Improving operations may allow the normal Pond elevation to be increased to
historic levels and/or allow the Dam to pass floods without requiring Pond drawdown in advance of storms.
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Town of Canton, Massachusetts SA Project No. 052-16-023A
RE: Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam,Canton, MA Page 4 of 14
Site Description and Background
Figure 1 —Site Location map and Figure 2 —Site Aerial Photograph show the location of Reservoir Pond Dam
(Site) on Pleasant Street in Canton, MA. The Dam discharges through a stoplog-controlled primary spillway
and an auxiliary (emergency) spillway. A gatehouse is located over the upstream opening of the primary
spillway. In various documents, the primary spillway is also referred to as "primary spillway," "primary
spillway conduit," or "gatehouse," etc., and the auxiliary spillway is also referred to as "auxiliary outlet,"
"conduit," etc. Furthermore, the portions of the primary spillway and auxiliary spillway that pass beneath
Pleasant Street are frequently referred to as "primary spillway culvert" and "auxiliary spillway culvert," For
consistency, SA has attempted, herein, to maintain the terminology used by others.
CDP owned the Dam and constructed repairs in each of summer 2012 and 2016 as part of a 2010 agreement
between the Town and CDP to transfer Dam ownership to the Town. The exact date of ownership transfer
(past or future) and ownership status (current owner), are unclear to SA, however•, it appears that ODS now
considers the Town as the Dam owner.
According to a Massachusetts Historical Commission Inventory Report dated October 2006, Reservoir Pond
Dam was reconstructed in 1931 by the Plymouth Rubber Co., replacing an earlier dam in 1827, which replaced
a dam constructed prior to 1720. The Dam was owned by the Plymouth Rubber Company until CDP obtained
the Dam in 2006. CDP's engineer subsequently prepared a Phase I Inspection and Evaluation dated June 11 &
20, 2007, providing an initial assessment of the condition. On May 19, 2009, SA, the Town, ODS and CDP's
engineer observed sinkholes at the primary and auxiliary spillways and in the impoundment upstream of the
auxiliary spillway, and failure of the masom•y wall at the auxiliary spillway. CDP's engineer subsequently
performed aPhase II Inspection/Evaluation, designed repairs, and prepared a Chapter 253 Permit application
to ODS dated April 22, 2011. CDP's engineer subsequently revised design drawings in August 2011 and
April 2012. ODS issued a Chapter 253 Permit on April 23, 2012. CDP subsequently constructed repairs in
2012 that consisted, generally, of removing vegetation, installing sheet piles and low permeability fill along
portions of the upstream face, and repau•s to the primary and auxiliary spillways. Soon after completion of the
2012 repairs, the Town noted uncontrolled seepage into the repaired auxiliary spillway and sinkholes at the
primary spillway. Following design of additional repairs by CDP's engineer, ODS issued a "Renewed"
Chapter 253 Permit on June 23, 2016 (in essence, a second Chapter 253 permit), and CDP constructed
additional repairs in summer 2016. CDP's engineer prepared a Chapter 253 Closure Report dated August 26,
2016 and ODS issued a Certificate of Compliance with Dam Safety Permit on November 17, 2016.
On November 25, 2016, the Town requested that SA observe significant uncontrolled seepage into and around
the primary spillway noted by the Town several days earlier. SA reported the seepage to ODS at the request of
the Town. ODS issued Dam Safety Orders on December 29, 2016, requiring a Poor Condition Follow-Up
Inspection (FUI) by January 18, 2017. On January 5, 2017 SA performed a Dam Safety FLJI on the Town's
behalf, and issued the Report on January 18, 2017 as required by the Dam Safety Orders. SA noted
uncontrolled seepage around and beneath the primary spillway and discharging from the auxiliary spillway
pipe and embankment toe to the right of the auxiliary spillway, resulting in a "Poor Condition" rating as
prescribed by ODS prescriptive criteria.
Subsequent to our FUI Report, the Town requested SA to evaluate the Dam by review of the
correspondence/actions to date, and to conceive of concept repairs/upgrades to address deficiencies identified.
This Report fulfills that request.
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Town of Canton, Massachusetts SA Project No. 052-16-023A
RE: Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam, Canton, MA Pale 5 of 14
Primary Spillway Review
SA reviewed the documents listed in Appendix Afor- issues describing. sinkholes, seepage, and repair of the
primary spillway. Information we noted is summarized below,in chronological order.
2010: The Phase II Inspection and Investigation Report prepared by CDP's engineer (Phase II Report)(2010)
summarized earlier indications of seepage and sinkholes, identified sinkholes and uncontrolled seepage at the
primary spillway as deficiencies, and recommended repairs of these deficiencies to mitigate uncontrolled
seepage. We noted the following:
The Phase II Report references evaluation of the Dam in October 1999 by Massachusetts Department
of Environmental Management(DEM, now Department of Conservation and Recreation, DCR ODS).
Regarding this DEM evaluation, the Phase II Report states, "The primary recommendations reported
in the(DEM)inspection summary indicated a need for standard maintenance and an investigation of
sinkholes observed near the primary spillway."
The Phase II Report summarizes a September 8, 2003 report by GZA GeoEnvironmental, Inc.
evaluating primary spillway sinkholes:
"GZA limited their investigations to the primary spillway, and indicated that they did not
observe the sinkhole(s); however, the ground near the gatehouse appeared soft. Based on
their investigations (including test borings), GZA recommended that the upstream masonry
headwall and primary spillway culvert be martared, grouting or compaction of loose fill be
performed, and a seepage cutoff wall near the primary spillway be installed to mitigate
potential seepage."
The Assessment section of the Phase II Report lists deficiencies, including, "5. Seepage into, and in
the vicinity of, the primary and auxiliary spillways." The caption for Photo #3 appended to the Phase
II Report indicates a sinkhole next to the primary spillway.
The Phase II Report recommended, "The masonry headwall, primary spillway culvert, and the
auxiliary spillway should be sealed (with new masonry) to mitigate uncontrolled seepage through the
upstream face of the dam," and,"The area surrounding the gatehouse and the auxiliary spillway should
be grouted to fill existing seepage channels and mitigate uncontrolled seepage. The intent of this work
is to grout the preferential pathways for seepage that have developed adjacent to the au~ciliary spillway
and gatehouse."
2011-2012: Design of repairs differed from the Phase II Report recommendations. CDP's engineer prepared a
Chapter 253 Permit Application to ODS dated April 22, 2011, accompanied by Design Drawings dated April
22, 2011. CDP's engineer subsequently prepared submitted to ODS Revised Design Drawings dated August
25, 2011 and April 17, 2012. The revisions were significant. While the Apri12011 Design Drawings specified
repairs (grouting) apparently to mitigate seepage around the primary spillway, neither the August 2011 nor
April 2012 Revised Design Drawings appear to implement the Phase II Report recommendations to seal
unmortared masonry in the primary spillway culvert and mitigate uncontrolled seepage around the primary
spillway by grouting. From review of the Chapter 253 Permit Application and the three sets of design
drawings, we noted the following:
• Sheet 3 of the April 2011 Design Drawings shows a shaded rectangle encompassing about 10 ft. left,
right and downstream of the gatehouse, called out as "grout and repair primary spillway." The design
report accompanying the Chapter 253 Permit Application states, "The proposed grouting along the
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Town of Canton, Massachusetts SA Project No.052-16-023A
RE: Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam, Canton, MA Pale 6 of 14
upstream embankment and within the vicinity of both the primary and auxiliary spillways is intended
to improve the embankment soils and reduce seepage through the dam."
• The August 25, 2011 Revised Design Drawings included no grouting around the primary spillway and
neither identified nor specified repair of sinkholes around the primary spillway. The April 17, 2012
Revised Design Drawings included a callout to repair sinkholes where encountered, but specified no
void filling that might mitigate seepage, nor did the design extend upstream sheet piles around the
primary spillway to cutoff seepage.
• SA reviewed the Phase II Report; April 2011 Chapter 253 Permit Application and Design Drawings;
August 25, 2011 Revised Design Drawings and specifications. SA prepared three letters dated June
21, September 9, and September 30, 2011, which the Town provided to ODS and ODS provided to
CDP's engineer on October 7, 2011. Our September 9, 2011 letter stated:
"Based on our review, we are concerned about the design, extent, suitability, and likely
longevity of proposed repairs to address deficiencies at the Dam such that the Town could
reasonably expect to limit their maintenance/repair costs for the near future and that would
allow the Town to operate the Dam with reservoir at the Bolt elevation while reducing risk
from dam operation, overtopping and/or breach. We are also concerned that the design is
incomplete; that analysis and design described in the Phase II Report and Revised Design
Drawings do not demonstrate compliance with 302 CMR 10.00 (Regulations); and/or, in our
opinion, there are serious questions/concerns over analysis and design assumptions and
results."
~ The April 17, 2012 Revised Design Drawings were subsequently approved, without provisions for
filling existing subsurface voids by grouting or other means, by ODS under the Apri123, 2012 Chapter
253 Permit.
2012: The 2012 Construction appears to have complied with neither the letter nor intent of the 2011 Chapter
253 Application and 2012 Chapter 253 Permit, as it repaired neither sinkholes nor subsurface voids caused by
uncontrolled seepage (or other causes) at the primary spillway as recommended in the Phase II Report, nor did
it repair primary spillway sinkholes as shown on the permitted April 17, 2012 Revised Design Drawings.
The As-Built Drawings attached to the December 21, 2012 Chapter 253 Closure Report show no
repairs of sinkholes at the primary spillway, no filling of voids around the primary spillway, and no
mortaring of the primary spillway culvert walls.
An August 15, 2012 field report by CDP's engineer (attached to the 2012 Chapter 253 Permit Closure
Report) states, "JDA (contractor) completed test pits adjacent to the primary spillway gatehouse to
evaluate the potential for sinkholes. No evidence of sinkholes observed," however, it describes neither
the depth nor extent nor observations of the test pits. The photograph included therein shows a test pit
perhaps 1 to 2 ft. deep. In our opinion, the test pits) should have extended at least as deep as the
culvert bottom elevation and we therefore question whether the test pits) extended deep enough to
evaluate sinkholes or their likely cause: underground voids created by uncontrolled seepage.
Nonetheless, the construction repaired neither the sinkholes nor seepage causing the primary spillway
sinkholes.
Stephens Associates
Consulting Engineers
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Town of Canton, Massachusetts SA Project No. 052-16-023A
RE: Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam, Canton, MA Page 7 of 14
2014: Town observed sinkholes near the primary spillway that developed post-construction, indicating that
construction did not address the cause of the sinkholes.
Based on emails between CDP's engineer and the Town between June 16, 2014 and August 28, 2014,
the Town apparently observed sinkholes on the right side of the gatehouse and downstream of the
gatehouse next to a gas line valve during that time period. CDP's engineer attributed the sinkholes to
surface water runoff, "soft ground, and water running along the pipe bedding." CDP's engineer also
"forced 200 gallons of water into the sinkhole (near the gas line valve) at a rate of approximately 3 to
5 gpm," with green dye. They noted that, "the dyed water entered (the primary spillway culvert) at an
immeasurable trickle approximately 3.5 ft. down from the top of the wall at approx. elevation 144.5
+/-." CDP's engineer gives no indication of where the majority of the water may have gone.
Despite the above, ODS requested that CDP's engineer add to repair design drawings "more detail on
the excavation and flow fill backfill to remediate the leakage and soil loss at the main spillway
conduit," in an October 29, 2014 email to CDP's engineer. It appears that ODS attributed the
sinkholes at the primary spillway to seepage. CDP's engineer responded on October 20, 2014 that,
"We will update the drawing sheet to further detail the sinkhole repairs,.." These emails are directly
referenced in the 2016 Renewed Chapter 253 Permit issued by ODS in conjunction with an October
16, 2014 Design Drawing, however, we note that the design drawing is dated before the emails and we
found no subsequently revised design drawing.
2016: The 2016 Renewed Chapter 253 Permit mandated evaluation and repair of sinkholes next to the primary
spillway, however, it appears that the Contractor made a cursory attempt to address the issue.
The 2016 Renewed Chapter 253 Permit describes background of the repairs to be constructed, noting
that a sinkhole developed after 2012 near the primary spillway gatehouse. It states that CDP's
engineer, "has also agreed to implement a sinkhole repair and infiltration prevention feature. This
involves excavation and placement of flow fill to prevent future loss of embankment material into the
primary spillway conduit." Condition (e) of the permit required, "The excavation and backfilling of
the sinkhole in the vicinity of the gatehouse and primary spillway conduit must be overseen and
approved by the dam engineer. ...The dam engineer...must be present while the excavation and
backfilling of the sinkholes is accomplished." The dam engineer was CDP's engineer.
In the 2016 Chapter 253 Closure Report, the Certificate of Completion provides a brief description of
the project, including, "Expose small sinkhole and pour flowable fill in any voids that exist near the
primary spillway gatehouse." The Closure Report includes no other documentation of extent of
exploration, evaluation or repair of sinkholes next to the primary spillway, except that a July 6, 2016
Daily Field Report, states that the contractor "excavated, reset and placed excavatable flow-fill around
the gas utility access west of the gate house," which is at similar, if not the same, location as a
previously noted sinkhole. It further states that the contractor performed that work prior to arrival on-
Site of CDP's engineer, indicating it was done without observation by CDP's engineer, in apparent
contradiction to Condition (e) of the permit as described above.
In a December 9, 2016 telephone discussion between SA and Mr. Bernard Plante of CDP, Mr. Plante
stated that the repair contractor had excavated and investigated a small depression around the gas hand
hole, determined the cause to be groundwater flow, filled the hole, and assumed the issue was fixed.
Mr. Plante generally said the contractor had made a good faith effort to repair the issue, but that they
may have misinterpreted the cause and therefore insufficiently repaired it.
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Town of Canton, Massachusetts SA Project No.052-16-023A
RE; Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam, Canton, MA Page 8 of 14
Condition (h) of the permit stated, "Since this permitted repair effort is to remediate infiltration into
the auxiliary and primary spillway conduits an Observation Report must be completed after the
reservoir is brought up to the normal summer level (elevation 145.6). Once the lake is returned to its
normal summer• level and after a reasonable time to allow groundwater levels to stabilize, field
observations of any infiltration into the conduits must be made. A report documenting these
observations including any concerns noted or items requiring future or immediate actions must be
submitted to ODS and the Town of Canton." We found neither apost-construction Observation Report
nor documentation of post-construction observations for seepage by CDP's engineer, as was required
by Condition (h) of the Permit.
2016-2017: Less than one month after ODS issued a Certificate of Compliance for the construction, the Town
and SA observed significant, uncontrolled seepage flowing through voids on the right side of the primary
spillway, and entering the primary spillway culvert, as evidenced by dye tests. As a result of the observed
uncontrolled seepage, SA rated the Dam as "Poor Condition" as prescribed by ODS inspection requirements,
as described in our FCTI Report, and summarized below.
Auxiliary Spillway Review
SA reviewed the documents listed in Appendix A for issues describing sinkholes, seepage, and repair of the
auxiliary spillway. Information we noted is summarized below, in chronological order.
2009: ODS issued a Certificate of Non-Compliance and Dam Safety Order to CDP following its observation of
failure (collapse) of the stone masonry wall near the auxiliary spillway inlet, worsening sinkholes around the
auxiliary spillway, water discharging into the auxiliary spillway sides, and sinkholes in the impoundment.
Follow-up Inspection by CDP's engineer attributed these deficiencies to uncontrolled seepage and internal
erosion. The June 15, 2009 Poor Condition Follow-Up Inspection identified a sinkhole on the north side of the
auxiliary spillway that "is estimated to be approximately 8 feet long along the headwall, 4 feet wide and 4.5
feet deep below the sidewalk. The sinkhole appeared to have been formed by the loss of soil as a result of
uncontrolled seepage in the area of the auxiliary spillway."
2010: The Phase II Report recommended auxiliary spillway repairs to mitigate uncontrolled seepage, as quoted
above in the previous section. It further states, "erosion tunnels were observed in the soils in sinkholes
upsheam of the auxiliary spillway."
2011: The 2011 Chapter 253 Permit Application states, "The proposed repairs to the auxiliary spillway consist
of the relining of the culvert downstream of the sharp-crested weir to prevent seepage tl~rocrgh tl~e culvert's
sidervnlls (emphasis added). A high density polyethylene (HOPE), or approved equivalent, sleeve will be
placed inside the existing culvert..." The referenced "sharp-crested weir" is the auxiliary spillway inlet. The
April 17, 2012 Revised Design Drawings show the upstream end of the pipe located 10 ft. downstream of the
stone masonry headwall and the area surrounding the spillway inlet to the upstream end of the pipe [o be filled
with concrete (Sheet 3). Note 4 on Sheet 6 directs the contractor to repair "...the auxiliary spillway training
walls and connect the proposed HOPE culvert pipe" (to the training walls). The text and the drawing,
together, indicate to us the intent to create a sealed spillway comprised of the spillway inlet (weir) and new
pipe extending from the spillway inlet to the downstream toe of the dam to prevent seepage from entering the
spillway sides. ODS later stated in a March 10, 20141etter that"ODS interpreted the (GOP's engineer) design
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Town of Canton, Massachusetts SA Project No.052-16-023A
RE: Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam,Canton, MA Page 9 of 14
to be inclusive of addressing conduit infiltration concerns." The April 2012 Design Drawings also specified
excavation to explore and fill sinkholes around the upstream end of the auxiliary spillway.
2012: Construction differed markedly from the designed and permitted repairs, neither relining nor sealing the
full length of the culvert. The December 21, 2012 As-Built Drawing Sheet 2(in the 2012 Closure Report) was
a new drawing (i.e. not a drawing of the Ch. 253-permitted design set), and shows the new HDPE pipe
upstream end about 35 ft. downstream of the stone masonry headwall, with stone and mortar culvert walls and
"existing earthen culvert floor" upstream of the pipe. Based on this Drawing, rather than a continuous
structural element, the auxiliary spillway "culvert" appears to be more of ahighly-variable, below-ground
opening, supported by varying, discontinuous materials along its length, including concrete, mortared- and un-
mortared stone and rubble masonry, bricks, granite blocks, soil (on the bottom), and/or an HDPE pipe, also
with a 12-in. dia. water pipe crossing tluough the opening. The culvert, post construction, is not a sealed,
relined conduit described by the 2012 Chapter 253 Permit Application and permitted Revised Design
Drawings.
2013-2014: The Town of Canton observed uncontrolled seepage entering the interior of the auxiliary spillway
culvert on February 28, 2013, indicating seepage problems were not fully mitigated by the 2012 repairs.
CDP's engineer periodically observed the dam and water inflow until December 2013, concluding that the
seepage was normal, minor and controlled. ODS issued four letters to CDP's engineer between March 2013
and 2014 disputing CDP's conclusion, requiring repair, and expressing concerns of dam safety:
March 20, 2013, ODS requested that CDP's engineer submit a plan to remediate the infiltration (i.e.
seepage).
May 23, 2013, ODS noted that "Seepage is continuing to spill into the auxiliary spillway conduit.
Therefore, it appears that this portion of the design intent of the repair plan (i.e. the 2012 repairs) has
not been met. ODS again requests that a remediation plan to address this undesirable seepage be
developed by(CDP's engineer) and presented to us and the town of Canton."
August 8, 2013, ODS noted that, "Considering that conduit infiltration is continuing to occur at these
locations (the auxiliary spillway) following completion of the dam repair project, and remediation of
this deficiency was a primary element of the permitted repair plan, it appears that the repair plan did
not adequately address the conduit infiltration deficiency. Furthermore, since (CDP's engineer) and
the contractor acknowledged in the Closure report that the project was completed in accordance with
the plans and specifications ODS questions whether the design was sufficiently adequate to address
this deficiency." It adds, "Infiltration into the conduit is not acceptable."
March 10, 2014, ODS stated,
"it is ODS's position that the observed seepage that increases as the pool rises in response
to runoff events within the normal range of operation is not "controlled, "normal" or
"minor seepage".... ODS finds the (CDP's engineer's) position as presented in the
December 13, 2013 report unacceptable...we believe that the continued uncontrolled
seepage that is occurring throughout the normal operating range of this dam and reservoir
could lead to future dam safety concerns. ODS has a difficult time understanding how this
seepage could be termed "controlled" as there are no filter provisions along the external
walls of the auxiliary conduit or elsewhere that would prevent the migration of fines
through the dam embankment. This condition could result in the loss of embankment
material and lead to future stability issues....."
Stephens Associates
Consulting Engineers
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ro-asr~w~e Hydrology &HydraulicsSource page 31
Town of Canton, Massachusetts SA Project No.052-16-023A
RE: Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam, Canton, MA Page 10 of 14
CDP's engineer subsequently designed additional repairs in July and October 2014 that added new
concrete walls inside a +/- 9-ft. long portion of the auxiliary spillway culvert, but made no
improvements to the culvert earth floor nor stone masonry walls, nor filling of embankment voids, to
seal the culvert or mitigate seepage around the culvert;
ODS's email to CDP's engineer of August 29, 2014 reviewing preliminary design drawings dated July
2014 questioned the extent of proposed repairs, "Based on your knowledge of the infilt~•ation into the
(auxiliary spillway) conduit, does the new wall system, as shown, extend far enough into the dam to
prevent further infiltration into the culvert?" CDP's engineer replied on September 14, 2014 that,
"The proposed wall section extends concrete facing further downstream than the seepage pathways
identified by (CDP's engineer) and the Town of Canton, to provide a higher level of seepage control in
the auxiliary spillway culvert. ... groundwater levels through the dam are located above the bottom
elevation of the auxiliary spillway culvert floor; therefore, typical, controlled seepage will continue to
discharge out the auxiliary spillway culvert pipe from the earthen culvert floor." This contradicts
ODS' previous statements that such seepage is "uncontrolled," however, the documents give no
indication of further correspondence between ODS and CDP's engineer on the topic.
2016: ODS issued a Chapter 253 Permit dated June 23, 2016, CDP constructed repairs reportedly between
June 27 and 30, 2016, and CDP's engineer prepared a Closure Report dated August 26, 2016. According to
the Auxiliary Spillway As-Built Plan (in the 2016 Closure Report), the new concrete walls extended from
about 10 to 19 ft. downstream of the auxiliary spillway headwall, and were constructed inside the existing
stone masonry walls. The drawing does not indicate repairs made outside the stone masonry walls, such as
filling of voids or seepage channels, nor repairs over the approximately 16 ft. length between the end of the
new concrete walls and the upstream end of the HDPE pipe. We found no post-construction Observation
Report or documentation of post-construction observations for seepage by CDP's engineer, as was required by
Condition (h)of the Permit, and described above.
2017: SA observed seepage exiting the downstream end of the auxiliary spillway and at the embankment
downstream toe on January 5, 2017, as described below. It appears that the seepage that formerly flowed into
the auxiliary spillway was not mitigated and is discharging from the embankment.
Poor Condition Follow-Up Inspection
In response to ODS Dam Safety Orders issued to the Town, SA performed a Poor Condition Follow-Up
Inspection (FUI) on January 5, 2017, as described in our Follow-Up Inspection Report dated January 18, 2017
and submitted to the Town separately. We summarize some key points herein. Our FUI was a limited, visual
observation of the primary spillway for uncontrolled seepage previously noted by ODS and the Town, and of
the downstream end of the auxiliary spillway culvert. Our FUI was not a detailed Phase I
Inspection/Evaluation. During the FUI, SA noted additional deficiencies (compared to the most-recent Phase I
Inspection by CDP's engineer dated December 17, 2012), including:
Uncontrolled seepage around and beneath the primary spillway: During dye testing, SA observed
dyed water flowing from the pond into the riprap on the right upstream side of the primary spillway,
immediately in front of the sheet piles. The Town reported that, on previous occasions (at lower water
elevations), dye also entered the stone masom•y headwall right of the primary spillway just above the
concrete cap of the sheet piles. SA observed the dye discharging into the primary spillway culvert
from the right sidewall; upwelling through a small hole in the base slab; from beneath the end of the
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Consulting Engineers
hxynn~~.co~~~ Structural
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Town of Canton, Massachusetts SA Project No.052-16-023A
RE: Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam, Canton, MA Page 11 of 14
concrete base slab; and from the bottom of the right, and possibly left, sidewall near the concrete base
slab end. SA also looked through a void between boulders in the right sidewall, about waist-height, to
observe water flowing roughly parallel to the culvert behind the side wall tlu•ough a void, roughly 1-ft.
diameter, between boulders at similar elevation to the concrete base slab;
Scour/erosion of the primary spillway culvert bottom (scour hole) downstream of the end of the
concrete slab;
Ground surface depression on the right side of the gatehouse, a few inches deep, roughly circular in
plan, about 1 to 2 ft. diameter;
Uncontrolled seepage at the auxiliary spillway: SA observed clear water discharging on the order of 5
gpm or less from the embankment toe, about 4 ft. right of the downstream end of the auxiliary
spillway. Discharge from the auxiliary spillway pipe was on the order of 2 gpm or less. SA observed
no water entering the upstream end.
We recommended that the Town remove stoplogs to two stoplog-heights below the bottom of sandbags,
thereby lowering the Pond, until repairs can be designed, permitted and constructed to mitigate the seepage.
We also recommended further evaluation, design, and construction to repair deficiencies and maintain the
Dam. As a result of the uncontrolled seepage, SA rated the Dam as "Poor Condition" under ODS prescriptive
criteria.
Goals, Alternative Concepts, and Cost Estimates
Possible Town goals are listed above in the Summary section. We understand that the Town would prefer to
maintain Reservoir Pond (the impoundment) for its use for recreation, aesthetics, cultural and/or water
resources, waterfront, etc., rather than decommission (remove) the Dam, which would significantly reduce, if
not eliminate, the pond. To maintain Reservoir Pond at similar elevations as in the past requires repairing the
Dam to address current deficiencies, at minimum. Based on the Dam's size and hazard classification, current
deficiencies, the "Poor Condition" rating, and apparent goal of the Town to maintain the impoundment, in our
opinion, to "Do Nothing" is neither viable, nor would it likely be allowed by ODS.
Based on our document review and Follow-Up Inspection, and as listed above under the Summary section,
current deficiencies generally consist of uncontrolled seepage through the embankment as well as into the
spillway culverts. In our opinion, uncontrolled seepage has been occurring for considerable time and has
resulted in voids in the embankment that were not fully filled in the previous repairs. A primary objective of
the repairs are therefore to control seepage and to fill existing voids to reduce risk of internal
erosion piping/ground loss, thereby reducing risk of dam failure, and improving the condition rating.
In addition to repairs, the Town might consider improvements to meet one or more goals for operation. For
example, the current Operation and Maintenance Plan (O&M Plan) prepared by CDP's engineer specifies a
summer normal pool at El. 145.6 (NAND 1988), a winter pool one foot lower, and drawdown of the
impoundment to El. 144.6 or lower in anticipation of storms. The Town might consider evaluating
improvements that might allow operation at higher normal pool, such as the historic "copper bolt" elevation of
146.1 ft., or operations that do not require drawdown in advance of storms. Such improvements would likely
require primary and/or auxiliary spillway modifications that increase discharge capacity.
We conceived of several, and selected ttuee alternative concepts (A, B, C)to address current deficiencies and
repair/upgrade the dam, depending on possible Town goals. Alternative A includes repairs to the embankment
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Town of Canton, Massachusetts SA Project No.052-16-023A
RE: Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam,Canton, MA Page 12 of 14
and primary and auxiliary spillways to control seepage and fill voids. Alternative A consists of minimum
repairs necessary to address current deficiencies and upgrade the Dam rating from Poor to Fair or better while
maintaining the operational conditions described in the O&M plan. Alternative B would address currently
identified deficiencies, enhance serviceable life and upgrade operation potentially to increase impoundment
height, and includes embankment repairs and replacement of the spillways to better control seepage, reduce
risks, and reduce future maintenance and repair costs. Further, in replacing the spillways, improvements to
operations and discharge capacity could be designed and the O&M Plan revised accordingly. Alternative C
addresses identified and unidentified deficiencies, further enhances serviceable life and upgrades operations.
It includes reconstructing the Dam and replacing the spillways to further control seepage, reduce risks and
future operation, maintenance and repair costs, and to improve operations. We considered other alternatives
such as "Do Nothing" as described above, and grouting. For various and differing reasons we excluded them
from our concepts as we judged them to be not viable, practical or practicable.
More detailed descriptions of the Alternatives are below. Sketches of Alternatives A and B are presented in
Figures 3 and 4, respectively. We did not sketch Alternative C to reconstruct the embankment and replace
spillways because of the variety of forms that reconstruction could take, as described below.
Alternative A: Repair Emba~zk»zerzt a~~d Pri»za~y and Ac~xilia~y Spillways
• Minimum repairs necessary to address current deficiencies and upgrade the Dam rating from Poor to
Fair or better while maintaining the operational conditions described in the O&M plan;
• Install additional sheet piles along the upstream face of Dam, between the two segments of sheet piles
already constructed, and extending around (in front and left of) the primary spillway. The sheet pile
installation would be accompanied by some excavation and backfill with low-permeability fill,
flowable fill, etc. The intent is to reduce seepage;
• Install a filtered drain system to capture seepage, reduce soil migration (i.e. internal erosion), and
discharge the seepage downstream. The drain would likely be located along the primary and auxiliary
spillways and either on the downstream side of the stone masonry headwall or near the downstream
toe, depending on analytical results. The intent is to control the seepage passing the upstream sheet
piles;
• Excavate at locations of previously- and currently-known sinkholes to evaluate and fill subsurface
voids; and
• Repair primary and auxiliary and spillways by mortaring stone masonry walls and excavating along
each side of each spillway and backfilling with flowable fill to fill voids and reduce seepage entering
the culverts. Also, concrete bottom slabs would be installed in each culvert where not currently
present, and voids under the primary spillway concrete slab would be filled. The intent is to reduce
seepage entering the culverts thereby reducing the risk of redevelopment of uncontrolled seepage
through internal erosion.
Alter~tative B: Repair EmbnnkmerTt and Replace Pri~na~y and Auxiliary Spilltivays
• Address currently identified deficiencies, enhance serviceable life and upgrade operation potentially to
increase impoundment height;
• Install upsheam sheet piles as described above for Alternative A;
• Install filtered drain system as described above for Alternative A;
• Fill voids along primary and auxiliary spillways as described above for Alternative A;
• Replace primary and/or auxiliary spillways and their culverts (e.g. with new reinforced concrete box
culverts, etc.) to reduce seepage infiltration. The intent is to provide "sealed" conduits consistent with
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Town of Canton, Massachusetts SA Project No.052-16-023A
RE: Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam,Canton, MA Page 13 of 14
modern Dam engineering, thereby reducing risk of internal erosion from uncontrolled seepage into
culverts; and
• As part of the spillway replacement, on behalf of the Town we could explore significant upgrades/
enhancements -modifications to primary and/or auxiliary spillway configuration to potentially allow
the Dam to pass the Spillway Design Flood without draw-down, and/or potentially allowing the Dam
to operate at a higher normal pool. SA did not sketch such improvements, though we believe that such
improvements could likely be accommodated within the range of costs estimated.
Alternative C: Reconstra~ct Dam
• Address identified and unidentified deficiencies, further enhance serviceable life and upgrade
operation to increase impoundment height;
• The Dam could be reconstructed, such as by excavation and replacement, installing a concrete seepage
cutoff trench, and/or grouting, etc. to reduce and control seepage, along with replacing the spillways
and incorporating improvements to discharge capacity.
SA estimated financial costs (i.e. cash outlay) in 2017 dollars for each alternative, as tabulated in the Summary
section. As described in Note 1 to the table in the Summary section, the costs are based on preliminary
concepts and are intended to provide order-of-magnitude costs for comparison and decision making.
Additional Limitations
Stephens Associates Consulting Engineers, LLC (SA) has prepared this Report based on the information
available to us at this time, including but not limited to, information furnished through the Client, the Owner
and their representatives for the proposed Project and cited herein. If any of the noted information is incorrect
or has changed, SA should be notified and retained to review the corrections and changes and amend this
Report. If SA is not retained for these purposes, we cannot be responsible for the impact of those conditions
on the performance of the Project.
SA reviewed documents in the attached list that were provided to us by the Town of Canton. Our purpose was
[o evaluate current status of the Dam by reviewing design, permitting and construction of recent repairs. The
scope of our services under our cun~ent agreement included neither review of accuracy of designs and/or
calculations, nor feasibility, suitability, or practicability of repairs to achieve goals (stated or otherwise). SA
has not performed a detailed check for regulatory compliance of design and consh•uction. Our comments
regarding compliance with regulations and/or permits are incidental to our review for the stated purpose.
SA conceived of alternatives based on our document review and limited Follow-Up Inspection (FL1I) described
herein. SA relied on these data for cost savings to Client in lieu of generating these data ourselves at higher
cost. SA has not performed amore-detailed Phase I Inspection/Evaluation that might indicate other
conditions/deficiencies, in addition to those described herein, which might also need repair. We
conceptualized the alternatives described herein based the current (January 2017) configuration of the Dam,
post-2012 and -2016 repairs as we understand from our document review and Poor Condition Follow-up
Inspection.
SA's scope of services did not include an environmental assessment of any kind, including but not limited to
assessments for the presence or absence of wetlands, hazardous or toxic materials or organisms (e.g., fungi,
flora, fauna, microorganisms, etc.) in the soil, surface water, groundwater, or air, on, below or around this Site.
Stephens Associates
Consulting Engineers
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Town of Canton, Massachusetts SA Project No.052-16-023A
RE: Dam Evaluation and Concept Repairs January 31, 2017
Reservoir Pond Dam,Canton, MA Page 14 of 14
Any observations of odors, colors, or unusual or suspicious items or conditions noted by SA were incidental to
our services, and any statements regarding such observations are strictly for the information of the Client.
This Report has been prepared by SA for the exclusive use of the Client and for the specific application to the
subject Project, as conceived at this time. The Report is for conceptual design only, and by itself is not
sufficient to prepare an accurate cost estimate or construction "bid." Subject to the limitations inherent in the
agreed scope of services, degree of cac•e, amount of time and expenses to be incurred, and any other limitations
contained in the Agreement for SA's services, SA has performed its services with the degree of care and skill
ordinarily exercised by other professional engineers under similar circumstances at the time the services were
performed. No warranties are implied or expressed.
This Report fulfills and completes our scope of services under Amendment lA of our Agreement. We trust it
is sufficient to meet your current needs. If you have any questions, or require clarification, please contact us at
(978)988-2115 or at the email addresses below.
Sincerely,
Stephens Associates Consulting Engineers,LLC
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Nathaniel A. Olson, PhD,PE James E. Turner, PE
Project Engineer Project Manager
NAOlson@StephensEngineers.com JETurner@StephensEngineers.com
Robert S. Stephens, PE
Principal Engineer
RSStephens@StephensEngineers.com
RSS/JET:tgbg
Attachments: Figure 1 —Site Location Map
Figure 2—Site Aerial Photograph
Figure 3 — Alternative A Sketch
Figure 4 — Alternative B Sketch
Appendix A —References
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f~rojec~: Number: 052-16-023A Sheet 1 of 1
Name: Reservoir Pond Dam, National ID MA00166
Original Work: Canton, Massachusetts
By: J. Turner Date: January 13, 2017 Subject: FIGURE 1 -Site Location Map
Checked By: Date:
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Project: Number: 052-16-023A Sheet 1 of 1
Name: Reservoir Pond Dam, National ID MA00166
Original Work: Canton, Massachusetts
By: J. Turner Date: January 11, 2017 Subject: FIGURE 2 -Site Aerial Photograph
Checked By: Date:
Approximate
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and obtained by MassGIS from Google. http://maps.massgis.state.ma.us/map_ol/oliver.php
accessed January 11, 2017
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Project: Number 052-16-023A Sheet 1 of 1
Name: Reservoir Pond Dam, NID: MA00166
Original Work: Canton, Masschusetts
By: NAO Date: January 31, 2017 Subject: FIGURE 3 - Alternative A Sketch
Checked By: JET Date: January 31, 2017
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by SA from Reservoir Pond Dam Ch. 253 Permit Closure Report, prepared by Sanborn, Head &Associates, dated
December 21, 2012.
Approximate Approximate Scale:
North 50 ft.
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Consulting Engineers
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Project: Number: 052-16-023A Sheet 1 of 1
Name: Reservoir Pond Dam, NID: MA00166
Original Work: Canton, Masschusetts
By: NAO Date: January 31, 2017 Subject: FIGURE 4 - Alternative B Sketch
Checked By: JET Date: January 31, 2017
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by SA from Reservoir Pond Dam Ch. 253 Permit Closure Report, prepared by Sanborn, Head &Associates, dated
December 21, 2012.
Approximate Approximate Scale:
North 50 ft.
Copyright O 2017 Stephens Associates Consulting Engineers LLC
Stepil8ns ASSOCIdt@S
Revisions: ~O""'~"g~1te1
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APPENDIX A —REFERENCES
References reviewed b_y SA;
Massachusetts Department of Conservation and Recreation, Office of Dam Safety (2016),"Order to Conduct a
Dam Safety Follow-Up Inspection," issued to Town of Canton, December 29, 2016.
Massachusetts Department of Conservation and Recreation, Office of Dam Safety (2016), "Certificate of
Compliance with Dam Safety Permit," November 17, 2016.
Sanborn, Head &Associates, Inc.(2016),"Chapter 253 Permit Closure Report, Reservoir Pond Dam," August
25, 2016.
Massachusetts Department of Conservation and Recreation, Office of Dam Safety (2016),"M.G.L. Chapter
253 Renew Dam Safety Permit," issued to Sanborn, Head &Associates, Inc. On behalf of Canton
Development Properties, LLC,In Cooperation with the Town of Canton, June 23,2016.
Sanborn, Head &Associates, Inc.(2014), email to Massachusetts Department of Conservation and Recreation,
Office of Dam Safety, October 30, 2014.
Sanborn, Head &Associates, Inc.(2014), "Reservoir Pond Dam Auxiliary Spillway Repair Plan," October 16,
2014.
Sanborn, Head &Associates, Inc.(2014)Letter to Massachusetts Department of Conservation and Recreation,
Office of Dam Safety, "Response to Auxiliary Spillway Repair Plan Comments," September 19, 2014.
Massachusetts Department of Conservation and Recreation, Office of Dam Safety (2014) email to Sanborn,
Head &Associates, Inc., "RE: Reservoir Pond Dam," August 29, 2014 providing comments to
Preliminary Auxiliary Spillway Repair Plan.
Sanborn, Head &Associates, Inc.(2014)email from Stan Sadkowski to Jim Donovan, Town of Canton,"RE:
Reservoir Pond Dam," summarizing evaluation of sinkhole at primary spillway, August 28, 2014.
Sanborn, Head &Associates, Inc.(2014), email from Stan Sadkowski to Jim Donovan, Town of Canton,"RE:
Sink hole at control building," June 16, 2014.
Massachusetts Department of Conservation and Recreation, Office of Dam Safety (2014) Letter to Sanborn,
Head &Associates, Inc., "Auxiliary Spillway Culvert Infiltration," March 10, 2014.
Sanborn, Head &Associates, Inc.(2013)Letter to Massachusetts Department of Conservation and Recreation,
Office of Dam Safety, "Observations at Auxiliary culvert -Monthly Report No.6 -November 2013,"
December 13, 2013.
Sanborn, Head &Associates, Inc.(2013) Letter to Massachusetts Department of Conservation and Recreation,
Office of Dam Safety, "Observations at Auxiliary culvert -Monthly Report No. 5 -October 2013,"
November 1, 2013.
Massachusetts Department of Conservation and Recreation, Office of Dam Safety (2013), Letter to Sanborn,
Head &Associates, Inc., "Re: Auxiliary Spillway Culvert Infiltration," August 8, 2013.
Stephens Assceiates
Consulting Engineers
u~ynm,~.cou- Structural
~"'~S""`01~ Geotechnical
SA Project No.052-16-023A 1/31/2017 p. A-1 of 4 tha~~'y"' Hydrology&Hydraulics