HomeMy WebLinkAboutPEER REVIEW 1999 FORM 11 - SOIL EVALUATOR FORM
Page I
t4ORTH�,NDOVER
PLANNING DEWMAEN' Date.......2.......q.........
No. ................................... Commonwealth of Massachusetts
Kjom a►,Dcqez , Massachusetts
foil Suitability Assessment Sewage Disposal
PerformedBy: ...............................................................
Witnessed B Y
................................................................................................................................................................................................................................................................
Lmlion Address ot owner•,Nam. fVWOV-0GD
Address.and AT-N- PZTIV�Z W7154-1
T I-- I L4—1 Tekphone I IZ-7 -rWuA6-- s-T--
New construction ❑ Repair ❑
Offi ce Review
Published Soil Survey Available: No ❑ Yes
Year Published -110.1... Publication Scale Soil Map Unit .�'q14
DrainageClass WD-.. Soil Limitations ......................................................................I......................................................
Surficial Geologic Report Available: No ❑ Yes ❑
Year Published .... Publication Scale ..................
GeologicMaterial (Map Unit) .....................................................................................................................................
.......... .......... ...... ..........
Landform .......................................... ..................................-......... .q. .S ......................
Flood Insurance Rate Map: 2S—e50'?6 000 C�-2Yes
Above 500 year flood boundary No El
Within 500 year flood boundary No ❑ Yes ❑
Within 100 year flood boundary No ❑ Yes ❑
Wetland Area:
National Wetland Inventory Map (map unit) ........ ................
Wetlands Conservancy Program Map (map unit)..................................................................................................
Current Water Resource Conditions (USGS): Month
Range Above Normal ❑ Nor7!al Below Normal El
Q ssoH rr
Other References Reviewed: VS, 6, S-
Fonj II SOIL EVALUATOR FORM
Page 2
p&-cite Review
Time: Weather ...
Deep Hole Number ........ Date't��;��-qq
.....
Location (identify on site plan)
...................................................................................I........................................................
Land Use ....................... Slope (%I ...... Surface Stones .... Y......................................................
Vegetation . ...............................................................................................................................................
Landform ...............................................
position on landscape (sketch.on the back) ...............................................................
Distances from: Drainage WaV.--.�. .... feet
Open Water Body feet
Possible Wet Area feet Property Line .............•••••• feet
Drinking Water Well .............. fast Other ...................................
DEEP 0 ION TMTE LOG
Depth from Surface Soil Horizon Soil TaKture Soil Color Soil Mottling other
(USDA) (Munsell) (Structure,Stones,Boulders,
liniches► Consistency, 96 Gravel)
(,0C,
&oo 56. 6VA V,
-7
ze'= 6FAV St, I D14 e!S-/ 7S\OZVi3 l 00 S� --Jpr H 9V,
SY4112 20°i6 A94, S 5 4 GS
Of 3A1J-C)
parent Material (geologic) ..... ....................... Depth to Bedrock:
.....................................
pel3th to Groundwater: Standing Water in the Hole. W.4 Weeping from Pit Face: ... ..8......
Estimated Seasonal High Ground Water.
FORM it - SOM EVALUATOR FORM
Page 2
On-site review
*Z Weather �e.o........
Deep Hole Number . . ...... Date:,S.- 7q Time:.R.M.-
Location (identify on site plan) SEZ........ ..A. . ........................................................I........................................................................
.PI
LandUbe ............................ Slope N ....1.0...... Surface Stones .............Mu ......................................................
............................................................................................................................................................................
Landform ..........................I........................................I................................ ........................................................
Position on landscape (sketch.on the back) ...........................I.......................................................................................1........................
Distances from:
Open Water Body feet Drainage way...: . ••.. feet
Possible Wet Area -5�2... feet Property Line ........... feet
Drinking Water Well .................. feet Other .....................................
DEEP ORSERVATION HOLE LOG
Depth from Surface Soil Horizon Soil Texture Soil Color Soil Mottling Other
(USDAI (Munsell) (Structure,Stones,Bouloam,
(Inchar1 Consistency, %Gravel)
A LOD-rE
35" F>Lj too S15—
Vr-
SY 6'I'Z L) I-0 fA
6VAVt-S, ICNES/6, t' C'V'
-20"lo A W
Parent Material (geologic) ..... .................................................... Depth to Bedrock:qq
Death ja§LQ-UjLd WAIftL Standing Water in the Hole: ....... Weeping from Pit Face:
Estimated Seasonal High Ground Water: 3ZI.I.
FORM 11 - SOIL EVALUATOR FORM
Page 3
Deterrninatiori for Seasonal High Water Table
Method Used:
❑ Depth observed standing in observation hole................... inches
❑ Depth weeping from side of observation hole ................... inches
91 Depth to soil mottlesgZ.t3Z inches
❑ Ground water adjustment feet
Index Well Number Reading Date ................... Index well level...................
Adjustment factor Adjusted ground water level ........................................................
Depth of Naturally Occurring Pervious Material
�``l0
Does at leash feet of naturally occurring p ervious material exist in all areas
observed throughout the area proposed for the"soil absorption system? _\�
If not, what is the depth of naturally occurring pervious material?
Certification
I certify that on - O- (date) I have passed the examination approved by the
Department of Environmental Protection and that the above analysis was
performed by me consistent with the required training, expertise and experience
described in 310 CMR 15.017.
Date
Signature
FORNI 12 - PERCOLATION TEST
COMMONWEALTH OF MASSACHUSETTS
WOE-('{-} q�,C&DVC- L , Massachusetts
Percolation Test
Date: Time:
Observation Hole # P 2
Depth of Perc -30„+(_7 „' LC7 33'+10('- _�:-j
Start Pre-soak
End Pre-soak l , 2
Time at 12" 2.� 2'D'�_
Time at 9"
Time at 6"
Time (9„-6") ID
Rate Min./Inch
Site Passed Site Failed ❑
/� �
Performed By:
Witnessed By:
Comments: .... ........................................
�s
-3-
All work shall conform to the following plan(s) and special conditions: ' '
i>
12. Plan(s) :
Plan entitled, "Site Plan of Land", in North Andover, MASS, prepared by
Merrimack Engineering Services, dated April 12, 1995, signed and stamped by
Stephen E. stapinski, P.L.S.
13. This order supersedes all previous orders of conditions issued for this
project, DEP File #242-543.
14. This superseding order shall be included in all construction contracts and
shall supersede any conflicting requirements.
15. No work shall commence on-site until all appeal periods have elapsed and
this superseding order of conditions has been recorded with the Registry of Deeds
and the Department formally notified via the form provided at the end of this
order.
16. A copy of this superseding order as well as the plans and reports referenced
in Condition #12 shall be available on site while activities regulated by this•
order are being performed. Copies of said documents shall be provided to all
contractors and subcontractors who shall also be held responsible for compliance
with this order.
17. All work shall conform to the Notice of Intent and above-referenced plans
and supporting documentation unless otherwise specified in this order.
18. This order shall apply to any successor or assigns in interest or control
and any other party engaging in activity on the property identified in the Notice
of Intent.
19 . Members and agents of the Department and the conservation commission shall
have the right to enter and inspect the premises to evaluate compliance with the
conditions stated in this superseding order, and may require the submittal of any
data deemed necessary by the Department for that evaluation.
20. Special Conditions numbered 35, 36, 37, 38, 39 and 40 shall extend beyond
the superseding order, •in perpetuity, and shall be referenced as such in the
Certificate of compliance.
21 . The applicant shall notify the Department and the Conservation commission in
writing 48 hours before any activity is to begin on the project site and shall
request an on-site conference with the commission to ensure that erosion controls
are correctly located and installed prior to the start of work. At the same
time, the applicant shall provide the Department and the Commission with the
names(s) , addresses and telephone number(s) of the person(s) responsible for
ensuring on-site compliance with this order and his or her alternate.
22. Prior to the start of work, the applicant shall submit a construction
schedule/sequence to the Department for written approval. A copy shall be sent
to the commission at the same time.
23. Prior to the start of any work, wetland flags or markers shall be checked
and re-established if needed to ensure that wetland areas are properly identified
and protected.
5-3B
-4-
24. Prior to any earth moving activity, filter fabric fencing (instead of
haybales) and snow-fencing shall be installed upgradient of all resource areas
along the limit of activity between areas to be disturbed and the stream and
wetlands. The location of these barriers shall be as shown on the approved plan.
These barriers shall define the limit of disturbance and shall be maintained in
good repair until all disturbed areas have been stabilized with vegetation or
other means, or until the Department determines that control measures are no long
necessary. Upon removal of silt and snow fencing, soil surfaces which were
disturbed by the fencing shall be immediately loamed and graded (if necessary) by
hand, and seeded.
25. Prior to the start of work, the limits of construction (as noted on the plan
referenced in condition #12) shall be located and staked or flagged so as to be
visible to workers. These markers shall remain in place throughout the
construction phase.
26. Prior to requesting a Certificate of Compliance, the limits of construction,
as noted on the plan referenced above and also referred to in Condition #24,
shall be permanently marked on the property. Stone bounds or another method
approved by the Department shall be used.
27. During all phases of construction, all disturbed or exposed soil surfaces *
shall be brought to final finished grade and either 1) loamed and seeded in
accordance with USDA soil conservation service Guidelines for.permanent
stabilization, or b) stabilized in another way approved by the Department. Bare
ground that cannot be permanently stabilized within 30 days shall be stabilized
with mulch or any other protective covering and/or method approved by the USDA
soil conservation service.
28. Site grading and construction shall be scheduled to avoid periods of hight
surface/ground water. once begun, grading and construction' shall continue in an
uninterrupted manner to completion to avoid erosion and siltation of the stream
and wetland areas.
29. All erosion control devices shall be maintained to ensure their
effectiveness. At no time shall any sediment be deposited in 'th°e stream or
wetland.
30. The applicant shall immediately control any erosion problems that occur on
the site and shall also immediately notify the Department and the Conservation
commission. The Department reserves the right to require additional erosion
and/or damage prevention controls it may deem necessary.
31. The proposed driveway shall be graded in such a manner to direct stormwater
runoff in a northeasterly direction (away from the wetland and stream) .
32. There shall be no stockpiling of debris, fill, or excavated materials within
50 'feet of a wetland unless specifically permitted in writing by the Department.
Any soil stockpiled for 24 hours within 100 feet of a wetland shall be surrounded
by sedimentation fence and covered with plastic or canvas, or stabilized in
another manner acceptable to the Department in order to prevent soil from
entering the wetland or stream.
33. Any debris which falls into the wetland or stream shall be 'removed
immediately by hand.
34. During construction, equipment storage and refueling operations shall be
situated in an upland area at a distance of at least 50 feet from the wetland or
stream.
35. No sodium-based product shall be used during or after construction of the
control of ice and snow. This Condition shall remain in force permanently and
shall be recorded.as such on the Certificate of Compliance.
5-4B
r
—5—
36 . Pesticides, which include herbicides, shall not be used within 50 feet of
any wetland or stream. This condition shall remain in force permanently and
shall be recorded as such on the Certificate of Compliance.
37. No fertilizers shall be applied to lawn or garden areas within 50 feet of
any wetland or stream. This Condition shall remain in force permanently and
shall be recorded as such on the Certificate of Compliance.
38. No underground fuel tanks shall be installed within 100 feet of the wetland
or stream. This Condition shall remain in force permanently and shall be
recorded as such on the Certificate of Compliance.
39. Portions of the property which lie outside and downgradient of the line
denoted as the "limit of construction" on the plan referenced above shall remain
in a natural condition and shall not be mowed or otherwise disturbed. This
condition shall remain in force permanently and shall be recorded as such on the
certificate of compliance.
40. The back yard area shall not extend beyond the line denoted as "limit of
construction" on the plan referenced above. Vegetation and soils outside the
limit of construction shall remain in a natural condition and shall not be mowed
or otherwise disturbed. This Condition shall remain in force permanently and
shall be recorded as such on the Certificate of compliance.
41. Upon completion of the project, the applicant shall request a Certificate of
compliance from the Department and shall submit the following information with
the request:
a) A written statement by a professional engineer or land surveyor registered
in the Commonwealth of Massachusetts certifying compliance with the approved
plans referenced above and this superseding Order of Conditions and setting forth
deviations, if any exist;
b) Two sets of as-built site plans prepared by a registered land surveyor or
registered professional engineer showing grades, utilities, building footprint,
landscaping, and the locations of permanent markers. These plans shall include
the date(s) of field work.
42. Any proposed or executed change in the plans approved under this Superseding
Order shall require the applicant to file a new Notice of Intent with the
Conservation commission or to inquire of the Department and the conservation
Commission in writing whether the change(s) is substantial enough to require a
new filing. Any errors in the plans or information submitted by the applicant
shall be considered changes and the above procedures shall be followed.
41. The attached settlement Agreement is hereby incorporated by reference into
this order of conditions, and shall be recorded at the Registry of Deeds
with this Final order of conditions.
FINDINGS PURSUANT TO M.G.L. CHAPTER 30
SECTIONS 61 TO 62H INCLUSIVE
(M.E.P.A. )
The project as described in the Notice of Intent for DEP File #242-543 is
"categorically exempt" pursuant to the Implementation of the Massachusetts
Environmental Policy Act as adopted by the Secretary of Environmental Affairs.
This project is "categorically exempt" because the wetland thresholds established
under 301 CMR 11.26 (7) (a) of M.G.L. Ch. 30, sections 60 to 62H inclusive, have
not been exceeded.
This finding is only applicable to activities proposed for the above-
referenced file number before the Department of Environmental Protection,
wetlands Division. it does not relieve the applicant from complying with
additional M.E.P.A, requirements when applying for permits from other applicable
departments or agencies.
5-5B
Town of forth Andover
Planning Department
2 i Charles Street
North Andover,yfA 01345
Xw
............ ......... �:: .�
To: US �� 1. (� �� _ Fix:
From: `V Y" 1 Gate: I ct 01
Re: Pages:
CC:
❑Uraenl ❑For Review ❑Please Comment ❑P!e_qe Reciv ❑Please Rem,cle
iUbtes:
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(, A9 F R 11M7 AN COLER AND COLAN'I'ON I O FAX NO, 7819825490 P. 02
COL/�NTNI
ENGINEERS
FACSIMILE COVER SHEET - - -
To: Heidi GrifCn
Company: Planning Board
Phone: 978-688-9535
Fax: 978-688-9542
From: Jason Loiselle
Company: Coler& Colantonio, Inc.
Phone: 781-982-5400
Fax: 781-982-5490
Date: October 15, 1999
Pages including this
cover page: l
Comments:
Heidi,
We have reviewed the submitted "Water Quality Evaluation"for Lot#1 Dale Street performed by
Wetland Preservation Inc.dated October 5, 1999 for conformance with the Town's Watershed Protection
District Bylaws.This study indicates no significant impact to the Water Quality of Lake Cochichewick.
Reportedly,the proposed nitrogen loading will be 1/10 the required minimum,drinking water standard
and the proposed phosphorous loading will cause a 0.05% increase in the loading.The Ioadings,as
reported,were modeled using the development of the entire lot and are thus conservative in their results.
If you have any questions,please call me 781-982-5434.
Jason
XC: Jim hand (978)688-9573
Merrimack Engineering (978)475-1448
NOV-26-1999 FRI 04:44 PM COLER AND COLANTONIO FAX NO. 7819825490 P. 03
COL:ALN
� f ,
�IPIO
E-NGINEF'
February 19, 1996
Ms.Kathleen Colwell
Town of North Andover
146 Main street
North Andover,MA 01845
RE: Engineering Review
Lot I Dale Street
Special Permit
Derr Ms. Colwell:
As requested, Coler & Colantonio, Inc- has reviewed the submittal prepared by Merrimack
heation is not dated,however the plans are dated April 12, 1995.
A q Application for
Engineering Services. The App of this review is to evaluate the App
It is our understanding that the Purpose that the
conformance with the requirements of the Watt�s1994�It is our further undersltand understanding to to e
Special permit Application for a lot created prior
Bylaws dated"Final 10/13/94"are the governing regulations.
We offer the following comments:
1. The, p
arcel lies within the Watershed protection District tlands flank boats des of the site,
t
parcel of land on the southeasterly side of Dale Street. c
d limit of work is within 37.5 feet of wetlands along the
0 feet is a non he site
barn c side of
2. The propose requires a setback of 10
43 feet on the easterly side. The Bylaw
zone.
3,
The limits of the "Non-Disturbance" zone are not indicated r n the plan as required in the
Bylaw. The entire locus lies within the"Non-Discharge"
4. Are report addressing the impact of site development
on water poa duais�notLfamiCar hwith the
p
was prepared by Norntandeau Associates.
ears reasonable for the
qualifications of Normandeau Associate analysis tp of their esented appears to perform this
type of work should be provided. Board should also consider the
individual site except as noted below. t planning
lake due to other suttilar projects. We
incremental degradation of water qualityhe square feet of the site will be landscaped area. The
question the assumption that only 3700
plan indicates a zone of approximately 10 to 15 feet around the building and driveway as
the limit of work, This will be difficult
arfuture homeowner nert would wish to expand
limited construction work space. It is y
the yard area on the lot. A restriction on the deed limiting althe developed portion of the of
to the area stated should be required as pan of any pp
617-962-5400
Norwell,tot Accord Park orive.Suite One Paz 617-982-5400
Norwell,MA 02061.1685
NOV-26-1999 FRI 04;45 PM COLER AND COLANTONIO FAX NO. 7819825490 P. 04
5, The
elevation of the cellar floor in the proposed building n oun eyed in thel excavation for he
areas on site. It is likely that groundwater will wa The regulations
cellar and will be a problem relative to infiltlas onofoa `npnpwatper into the cellar.
Typically, this would be controlled through the un, is used this
recharge runoff to the extent feasible, if a sump p I? We
require that designs groundwater to a surface discharge point.
would have the effect of pumping g a certified soil evaluator to
recommend that a test pit be excavated groundwater tablet' The proposed cellar floor and
estimate the maximum seasonal high g
elevation should be a minimum of one foot above this elevation along the easterly side of the lect
6 The plans indicate a grass Swale which woul oCDalet Street. lt also appears that a small
building for discharge across the driveway
depression on the easterly side of the proposed dri a water in the layout of a public street,
be created. We do not recommend creating a trap pale Street. The all ey'IsE
The proposed Swale would te runoff from imperviousga eashbelot charged tthe report by
regulations require that st
feasible. The proposed Swale does not address this requirement. Based on
Normandeau Associates, soils on the site should be suitable for on-site recharge• side of
7
e timitG
It does not appear possible to grade to th and existing 198 contours,ln e westerly
the driveway in the vicinity of the proposed 1
to assist the Planning Board on this project and hope that this
We appreciate the opportunity questions please do not hesitate to
information is sufficient for your needs. If you have any
contact us.
very truly yours,
COLER&COLANTONIO,INC.
D��
r
Sohn C.Chessia,P.E.
xe Merrimack Engineering Services
J99 FR 1 10:61 AM COLER AND COLAKON 10 FAX N0, t81 J82b490 P. 02
Lo
COLANTONIOZ
ENGINEERS
FACSIMILE COVER SHEET
To: Heidi Griffin
Company: Planning Board
Phone: 978-688-9535
Pax: 978-688-9542
Prom: Jason lloiselle
Company: Coler& Colantonio, Inc.
Phone: 781-982-5400
Fax: 781-982-5490
Date: October 15, 1999
Pages including this
cover page: 1
Comments:
Heidi,
We have reviewed the submitted "Water Quality Evaluation"for Lot#1 Dale Street performed by
Wetland Preservation Inc.dated October 5, 1999 for conformance with the Town's Watershed Protection
District Bylaws.This study indicates no significant impact to the Water Quality of Lake Cochichewick.
Reportedly,the proposed nitrogen loading will be 1/10 the required minimurn drinking water standard
and the proposed phosphorous loading will cause a 0.05% increase in the loading.The loadings, as
reported,were modeled using the development of the entire lot and are thus conservative in their results.
If you have any questions,please call me 781-982-5434.
Jason
XC: Jim Rand (978)688-9573
Merrimack Engineering 078)475-1448
Town O f North Andover * VA RTH
0
OF]t CE OF 0
04
0
COMMUNITY DEVELOPMENT AND SERVICES
27 Charles Street
North Andover, Massachtisetts 01845
WILLIAM J. SCO-IT CHUS
Director
(978)688-9531 Fax(978)688-9542
MEMORANDUM
TO: North Andover Planning Board
FROM: Heidi Griffin,Town Planne
RE, Planning Board Agenda Item Update
DATE: October 14,1999
475 Dale Street: The Board requested the applicant to provide a more detailed water quality
evaluation with an explanation of the relation to the tributary on site that will eventually flow to Lake
Cochiewick and the effect the proposed building will have on the Lake. That report is included in your
packets for your review, and is quite concise and explanatory. I am also including a copy of the
stipulation referenced to this lot that the Board requested and which I had previously given to you.
492 Sutton Street: Bill Scott relayed to me that at the last meeting the Board indicated to Phil
Christiansen that he was supposed to present revised plans to the Planning Department so that I could draft
up a decision for the project. I have not received revised plans as of this date,and therefore I am unable to
draft up a decision for the 10/19/99 meeting.
BOARD OF APPEAI.S 688-9541 BUILDING 688-9545 CONSERVATION 688-9530 HEALTH 688-9540 PLANNING 689-9535
E T L A N D S
RESERVATION
INC.
Water Quality Evaluation
Lot #1, Dale Street
North Andover, Massachusetts
October 5, 1999
Prepared for
Peter Hatern
Hatern &Mahoney
127 Turnpike Street
North Andover,Massachusetts 01845
Prepared by
Wetlands Preservation, Inc.
47 Newton Road
Plaistow,New Hampshire 03865
VVTPI Job #2407A
475 Ipswich Road E-mail: wetlandwpi@greennet.net 47 Newton Road
Boxford, MA 01921 Fax: (603) 382-3492 Plaistow, NH 03865
(978) 352-7903 (603) 382-3435
Water Quality Evaluation
Lot #1, Dale Street
North Andover Massachusetts
Introduction
The purpose of the following evaluation is to assess the potential impacts to the quality of water
discharging to Lake Cochichewick from the development of a proposed residential house lot on Dale
Street in North Andover, Massachusetts. The proposed project entails the development of one
single-family home on an existing undeveloped parcel located on Dale Street. This study will focus
on water quality issues of site development and the potential increases to nutrient levels, in particular
phosphorus and nitrogen, to water discharging from the site and possible effects to downstream Lake
Cochichewick.
For this evaluation, the Lake Cochichewick Watershed Plan dated August 1987 and the more recent
lake study, an Evaluation of Water Quality and Management Options in Lake Cochichewick and Its
Watershed dated February, 1999, were reviewed and used for existing water quality conditions
within the lake and to evaluate consistency of project impacts with the goals set forth as part of the
Watershed Protection District.
Watershed Setting and Background
The proposed site is located within the Lake Cochichewick Watershed Protection Area. Lake
Cochichewick serves the Town of North Andover as the primary water supply source. Watershed
area to the lake is estimated at 2,732 acres (1,106 hectares) and the surface area of the pond
approximates 564 acres (228 hectares) (IEP, 1987). The average flushing rate or the rate at which
the quantity of water within the lake is completely renewed in percent volume per year is 0.57 (IEP,
1987). Previous monitoring of in-lake and discharge points tributary to the lake indicate increased
algal growth, occasional elevated levels of nutrients, turbidity, and bacteria were the principal
concerns for maintaining a high level of water quality in the lake (IEP, 1987). The town of North
Andover has invested a substantial effort in following the recommendations of the 1987 Watershed
Plan, but recent water quality sampling have shown these principle concerns are still valid (ENSR,
1999).
The lake has seven tributaries which make up the primary contribution of flow to the lake. The
tributaries were assigned names in the Lake Cochichewick Watershed Plan which were originally
given by a North Andover Town water chemist while conducting a monitoring program. The project
site of this analysis is located in the subwatershed to the Lake Cochichewick tributary called Batell's
Brook. Batell's Brook has a total watershed area of 380 acres (154 hectares) which makes up 13.9%
of the total tributary watershed to Lake Cochichewick. The primary land use the Batell's Brook
watershed is forested (43%), and residential (33%), with the remaining 24% being made up of
pasture, and open land (ENSR, 1999). The residential area in the upper reaches of this watershed has
increased from a total watershed percentage of 26% when the 1987 study was prepared (IEP, 1987).
The proposed project, assuming the entire lot area is developed would add less than 0.3% to the total
residential area in the Batell's Brook watershed.
1
The project site is located within upper reaches of the Batell's Brook watershed. Existing land use is
primarily undisturbed wooded uplands and wetlands. Stormwater runoff under existing conditions
flows overland to wetlands on the east and west property boundaries. The wetlands to the east and
west of the property are tributary to the large wetland on the north side of Dale Street which forms
the headwaters to Batell's Brook. Batell's Brook from this point flows in an easterly and then
northerly direction through a system of wetlands and small ponds to Lake Cochichewick The
shortest flow path from site boundaries to the lake is estimated at 1.34 miles (2,160 meters).
Proposed Project
The proposed project entails the development of a single family house lot adjacent to existing
roadway and necessary infrastructure. The proposed home is to be serviced by Town of North
Andover sewer and water lines and therefore no septic systems will be installed alleviating a major
potential source of nutrient loads. The proposed project has been designed to minimize land
disturbance and the associated water quality impacts by placing the actual home location as far away
from the wetlands as possible and limiting grading by blending the house lot into the existing
topography. Site plans limit the actual disturbance area to the one-acre site at 6,500 sf to
accommodate the structure (1,613 sf) and the driveway (1,200 so. For the purpose of this analysis, a
more aggressive grading plan was assumed using a disturbed area more than triple what is proposed
maintaining the limit of the 25-foot wetland setback giving a total disturbance area of 20,000 sf.
This was assumed to be a reasonable maximum disturbed area for the lot. The proposed roof runoff
is directed to a rooftop leaching system located on the western side of the proposed structure. The,
disturbed mot Y ion of the lot and the proposed driveway are graded to drain toward Dale Street to be
oll
cected in the roadwa storm s� stem.
Phosphorus Loading
In-lake phosphorus concentrations are often the determinant of the trophic state of a lake.
Phosphorus is generally the controlling nutrient for algal growth. The watershed plan prepared by
IEP (1987) documented monthly sampling during 1985 and 1986 to show a mean in-lake
concentration of phosphorus of 20 parts per billion (ppb). Data collected for the years 1994-1996 by
the North Andover Water Department showed the same in-lake concentration and allowed a
calculation of the average annual phosphorus load to Lake Cochichewick to be estimated at 1,183
lbs/yr (ENSR, 1999). This suggests Lake Cochichewick falls into the category of a mesotrophic lake
which typically ranges between 10.0 to 25.0 ppb (EPA, 1990). Average concentrations of total
phosphorus at the tributary discharge locations were elevated to high (25ppb and 50 ppb
respectively) in the 1985-1986 period and consistently high during the 1993-1997 period. This may
suggest some increase in the watershed phosphorus contribution but the limits of the data (frequency
and conditions of sampling, detection limits) do not allow for a strong or substantial comparison
(ENSR, 1999). From the data which are available it is evident that the loads into the lake may be
increasing and are not declining despite the attempts of watershed management by the town. One of
the goals of the 1999 watershed study by ENSR was to determine the potential role of internal
recycling as a threat to water quality. Although a change in the mean in-lake concentrations of
phosphorus has been undetectable, maximum hypolimnetic values were much higher in the 1993-
1997 data set. Again the limits of the data limit the conclusions that can be made, but it appears
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evident that the internal release of phosphorus from bottom sediments has increased since the 1987
Watershed Plan(ENSR, 1999). The ENSR study concluded that the tributaries appear to still be the
largest load of phosphorus to the lake but the potential load from the internal recycling should not be
ignored. The lake could be changing from a system governed by external inputs to one which is
driven by the internal process of recycling which commonly occurs during the process of
eutrophication.
Phosphorus loading estimates are developed using the loading coefficients and methodology
provided in the Watershed Plan (IEP, 1987). This analysis assumes the loading source from the site
is adjacent to and drains directly into the lake. In other words, it assumes the 1.34 miles (2,160
meters) of downstream drainage path does not exist. The Plan uses a loading coefficient for forested
wetland of 0.18 lbs/ac/yr, (0.20 kg/ha/yr). There is no differentiation for loading between forest and
forested wetland. Table 18 on page 67 of the Watershed Plan uses a "most likely" residential
loading coefficient of 0.38 lbs/ac/yr (0.43 kg/ha/yr). The original source for coefficients for use in
the Plan (Reckow, 1980) uses a loading coefficient of 1.0 lbs/ac/yr (1.12 kg/ha/yr). The 1.0 lbs/ac/yr
is used as a more conservative loading coefficient and is consistent with the total residential
contribution estimate which is discussed on page 69 of the Plan.
Existing conditions on the 1.0 acre (0.4047 hectare) site is wooded wetlands and uplands. The
existing annual load of phosphorus from this site to the lake is 0.18 lbs (0.20 kg) using the above
assumptions. The mitigative properties of phosphorus retention and annual load reduction in the
downstream wetlands and ponds between the site and the lake are not accounted for in this analysis
under existing or post development conditions. Were the mitigative properties downstream to be
considered, the annual load would be significantly reduced from that calculated above.
Under proposed conditions the site is represented by 0.46 acres (0.186 hectare) of residential
assuming a threefold increase to the area of disturbance as shown on the proposed plan, and 0.64
acres (0.256 hectare) of wooded wetland and upland which will remain undisturbed.
Under proposed conditions the site is estimated to contribute 0.58 lbs/yr (0.26 kg/yr) or a net
increase of 0.4 lbs (0.18 kg). Again, these calculations do not account for reductions to the proposed
loadings which would occur due to mitigative properties of downstream areas before discharging to
the lake.
The impact on Lake Cochichewick from the increase in phosphorus loading is analyzed using a
modified version of the input-output model developed by Vollenweider(1976). This recognized and
widely used model has gained international acceptance as the preferred method of evaluation. The
model is modified to analyze relative changes in phosphorus loading to determine trophic state
relationships and is expressed below.
ATP =AL (1/(V�p+p))
where: ATP =the change in in-lake total phosphorous concentration in ppb
AL =the change in total phosphorous loading in kg/yr.
V =Lake volume in m'x 106
p =Lake flushing rate per year
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Using a lake volume of 16.2 x 106 in' and a flushing rate of 0.57 per year, it is estimated that the
maximum impact of the proposed project would be an increase to in-lake phosphorus concentrations
of 0.01 ppb.. The total phosphorus data collected by IEP for the Watershed Plan showed a mean in-
lake concentration of 20.0 ppb (1987), which was verified again by ENSR in the more recent
investigation (1999). Therefore the estimated increase in phosphorus concentration would represent
less than 0.05% increase over mean annual levels. Given today's standard analytical techniques the
estimated increase in proposed levels is essentially immeasurable and well within the expected range
of natural variability.
The results of this phosphorus analysis are on the conservative side and the impacts are expected to
be much less than has been estimated due to the many natural mitigative structures downstream.
This proposed residential house lot which is tributary to the lake is treated first by the natural
wooded filter strip which will be maintained as required by the 25-foot, non-disturbance zone. Filter
strips can remove up to 60% of the total phosphorus load (Schueler, 1987). The extensive wetlands
which exist downstream of Dale Street and the site wetlands will also reduce the phosphorus load.
The EPA (1983) reported that wetlands have been found to be greater than 80% efficient in
removing phosphorus except during winter months when removal may drop to 25% to 35%. The
ponds downstream of the wetlands will even further treat the runoff from the site before discharging
to the lake. Wet ponds such as this are expected to remove 80% of phosphorous loads (Schueler,
1987).
II
Nitrogen Loading
A nitrogen loading analysis was performed to determine if average annual concentrations of nitrogen
would exceed the l0mg/I drinking water standard. All of the nitrogen loading from this site will be
in the form of stormwater runoff as no septic systems will be installed. Published loading
coefficients for residential areas include contributions from septic systems and lawn fertilizers.
Loading coefficients were not reduced because of the lots being hooked to town sewer as there is a
lack of information concerning the weighted proportions of the singular contributions from either the
septic systems or fertilizer use alone. The empirical total nitrogen coefficients for residential and for
forested areas are 5.3 (5.9), and 2.5 lbs/ac/yr(2.8 kg/ha/yr),respectively(Reckhow, 1980).
Based on the above coefficients for loading and the existing and proposed site plans, the total annual
site export of total nitrogen is estimated as 2.5 lbs/yr (1.13 kg/yr) under existing conditions and 4.04
lbs/yr (1.82 kg/yr) under proposed conditions. The watershed plan presented annual runoff at
approximately 20 inches (510 min) for the Lake Cochichewick watershed. Therefore the one acre
(0.4047 hectare) parcel has a total annual site runoff volume of 0.072 x 10' W (0.21 x 107 1) and the
average annual nitrogen concentration is estimated as 0.54 mg/l and 0.87 mg/l under existing and
proposed conditions respectively. The nitrogen levels in runoff leaving the site will be well below
the 10 mg/l drinking water standard even when using the conservative loading coefficient which
assumes the use of septic systems which will in fact not be a part of this project.
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Summary and Conclusions
The nutrient loading analysis which has been based on conservative assumptions has shown minor
increases in both phosphorus and nitrogen export with the proposed plan. The minor increases will
have essentially no impact to the water quality of Lake Cochichewick. The downstream natural
BMPs including the wooded filter strip left undisturbed, extensive wetland systems and several
ponds along the course of the brook which will remove a considerable proportion of the nutrient load
from site runoff, but were not accounted for in this analysis, give further assurance that water quality
impacts from the proposed project will not be realized. In addition, the loading calculations
presented here assumed a site disturbance area of 20,000 sf when the present site plan calls for a
disturbed area of only 6500 sf. An actual disturbance area of less than 20,000 sf would further
decrease the expected negligible impacts to Lake Cochichewick.
Based on the results of the enclosed evaluation and analysis, it is our professional opinion that there
will be no significant degradation of the quality of water in or entering Lake Cochichewick as a
result of the proposed project.
References
ENSR. February 1999. An Evaluation of Water Quality and Management Options in Lake
Cochichewick and Its Watershed,North Andover, Massachusetts.
Environmental Protection Agency (EPA). 1990. The lake and reservoir restoration guidance manual.
Second Edition EPA 440/4-90-006.
Environmental Protection Agency(EPA). 1983. Results of the Nationwide Urban Runoff Program.
Volume 1. Final Report. Water Planning Division, Washington D.C.
IEP. 1987. Lake Cochichewick Watershed Plan. Final Report. August 1987.
Massachusetts Department of Environmental Protection and Office of Coastal Zone Management.
Stormwater Management. Volume One: Stormwater Policy Handbook. March 1997.
Reckow, K.H., M.N. Beaulac and JT Simpson. 1980. Modeling phosphorous loading and lake
response under uncertainty: A manual and compilation of export coefficients.
Schueler, T.R. 1987. Controlling urban runoff: A practical manual for planning and design urban
BMPs. Metropolitan Washington Council of Governments.
Vollenweider, R.A., 1976. Advances in defining critical loading levels for phosphorous loading in
lake eutrophication. Mem. Ist. Ital Idrobiol 33: 53-83.
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