36_-251_letterAD 21 Maple Ridge Rd- general informationPART I: GENERAL INFORMATION
Project Description
The project site is located on the northerly side of Maple Ridge Road approximately 200'
west of Florence Road (See Figure 1). The project consists of the construction of a single
family dwelling within the 100' Buffer Zone of a Bordering Vegetated Wetland. The
dwelling will be serviced by a subsurface sewage disposal system which will be greater
than 50' from the wetland boundary, but within the 100' Buffer Zone. A bituminous
concrete driveway will cross the Buffer Zone along an area previously prepared for such
a use. The wetland consists of a long swale which channels surface water runoff along
the easterly border of the subject property. The stormwater crosses under an existing
gravel roadway/driveway through a 12" reinforced concrete culvert. The culvert was
installed in the late 1980's to provide access to this lot in the Maple Ridge subdivision.
Construction shall be limited to the 100' Buffer Zone. No wetland will be disturbed as
part of this submittal.
7e. Filing, Fee
The filing fee for this project has been determined to be $285.00. It consists of the
construction of a single family dwelling, septic system, and driveway within the 100'
buffer zone of a bordering vegetated wetland. The construction is a Category 2 project
which requires a $250.00 filing fee. The additional $35 is a local filing fee payable to
the City of Northampton. Of the total filing fee, $112.50 is submitted to the
Commonwealth of Massachusetts with the remainder submitted to the City of
Northampton Conservation Commission ($172.50). See a copy of the two filing fee
checks, the Fee Calculation Worksheet, and the Fee Transmittal Form in Appendix 2.
PART II: SITE DESCRIPTION
A. Natural Features
1. Soils
Figure 2 presents the soil survey for the subject site, completed by the U.S. Soil
Conservation Service (taken from the Soil Survey of Hampshire County, Map 417). The
soil type shown to be at this site is Paxton very stoney fine sandy loam (PcC). Paxton
fine sandy loam is a deep and well drained soil. The permeability of this soil is moderate
in the subsoil and slow to very slow in the substratum. The substratum is very firm,
causing a high seasonally perched water table. Erosion potential of the Paxton soils is
low to moderate.
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The Soil Survey also indicated an area of Udorthents, which is an area that has been
disturbed at some point in history. The soils in this area could range in permeability from
slow to very rapid. Test pits excavated for soil evaluations and percolation tests found
very coarse sandy soils near Maple Ridge Road, while excavations farther into the parcel
(north of the wetland) confirmed the Paxton soils.
2. Vejaetation
The vegetative canopy at this site is dominated by mature Red Maple. The remainder of
the canopy includes Hemlock, White Pine, White Birch, and Red Oak. The shrub layer is
dominated by Winterberry Holly and young Honey Locust. Sensitive Fern, Cinnamon
Fern, and Soft Rush dominate the ground cover where sunlight can reach open areas of
the site through the canopy. A vegetation list has been included in Table 1.
3. Flowing Water Bodies
There are no flowing water bodies on this site. The drainage Swale carries stormwater
westerly, but no definitive stream channel exists.
4. Boundaries of Resource Areas
The resource area boundary was delineated in the field with blue surveyors flagging,
numbered from W 1 to W8 on the westerly side of the RCP culvert and E 1 to E6 on the
easterly side. The boundary of the Swale was determined based on vegetation and
topography since the swales were man-made and most of the soils were disturbed. The
Swale perimeter consists of well defined banks along the area closest to the proposed
work.
B. Man-made Features
I. Drainage and Flood Control Facilities
The wetland at this site is a direct result of the drainage system for the subdivision in
which the subject parcel is located. Stormwater runoff from the north easterly side of the
project is channeled, through man-made swales and concrete culverts, into a large
detention basin. Collected stormwater is then released to an un -named stream down
gradient of the site. The storm drainage system was constructed in the late 1980's. The
existing 12" RCP culvert under the roadway/driveway on this parcel was installed as part
of the original construction of the subdivision.
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TABLE 1: Vegetation identified on subject parcel on Maple Ridge Road,
Northampton, MA on April 30, 1996 by Pioneer Environmental. The Hydric
Indicator Status (H.I.S.) for each species was obtained from the National List of
Plant Species That Occur in Wetlands: 1988, Massachusetts.
Common Name
Scientific Name
*H.I.S.
**Abundance
Red Maple
Acer rubrum
FAC
5
Honey Locust
Gleditsia triacanthos
FACU
3
White Birch
Betula alba
FACU
3
White Oak
Quercus alba
FACU
1
Eastern Hemlock
Tsuga canadensis
FACU
3
White Pine
Pinus strobus
FACU
3
Red Oak
Quercus rubra
FACU-
3
Silky Dogwood
Cornus amomum
FACW
2
Mountain Laurel
Kalmia latifolia
FACU
2
Speckled Alder
Alms rugosa
FACW+
2
Swamp Rose
Rosa palustris
OBL
3
Cinnamon Fern
Osmunda cinnamoma
FACW
4
Sensitive Fern
Onoclea sensibilis
FACW
5
Christmas Fern
Polystichum acrostichoides FACU
2
Soft Rush
Juncus effusus
FACW+
4
Broom Sedge
Carex scoparia
FACW
3
Green Bulrush
Scirpus atrovirens
OBL
3
Broadleaf Cattail
Typha latifolia
OBL
3
* Hydric Indicator Status: See descriptions on next page
** See Abundance Key on next page
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INDICATOR CATEGORIES
OBL (Obligate Wetland): Occur almost always (>99%) in wetlands under natural
conditions.
FACW (Facultative Wetland): Usually occur in wetlands (67%-99%), but occasionally
are found in upland environments.
FAC (Facultative): Equally likely to occur in wetlands or uplands (34%-66%).
FACU (Facultative Upland): Usually occur in uplands (67%-990/o), but occasionally
found in wetland environments.
UPL (Obligate Upland): Occur almost always (>99%) in uplands under natural
conditions in this region. May occur in wetlands in other regions of the country.
A positive (+) or negative (-) sign is used with the facultative indicator categories to more
specifically define the regional frequency of occurrence in wetlands. The positive sign
indicates a frequency toward the higher end of the category (more frequently found in
wetlands), and a negative sign indicates a frequency toward the lower end of the category
(less frequently found in wetlands).
ABUNDANCE KEY
5: Very abundant; the only dominant species of that vegetative layer for the subject
area.
4: Moderately abundant; is a dominant species of that vegetative layer but may share
the dominance with one or two other species.
3: Somewhat abundant; is not a dominant species but can be found throughout the
subject area.
2: Uncommon; very few individuals scattered throughout the subject area. May occur in
isolated clumps.
1: Rare; represented by a single individual or occurs in a very low density throughout
the subject area.
2. Subsurface Sew a we Disposal Systems
There are no existing subsurface sewage disposal systems located on the subject parcel.
3. Underground Utilities
The only existing underground utilities at this site are a water service line and electric,
telephone, and cable TV. These services have not been extended into the site beyond the
front property line.
I Roadways and Parking Areas
There is no pavement on the subject parcel. An existing gravel roadway exists on the
parcel. This roadway was installed as part of the subdivision construction and intended
to be the driveway access to the building site on the lot.
5. Property Boundaries
The corners of the subject parcel are all marked with iron pins. Property boundaries and
dimensions have been shown on Drawing #98-025.
PART III: WORK DESCRIPTION
1. Structures
One single family home with a detached garage will be constructed within the buffer zone
as shown on the Site Plan. The dwelling will have a 12 foot wide bituminous concrete
driveway running from Maple Ridge Road to the proposed new structures. The proposed
house location is approximately 50' from the wetland boundary at its closest point and the
garage 65' at it closest point.
2. Drainage and Flood Control Facilities
No new drainage or flood control structures are proposed under this submittal.
3. Subsurface Sewa a Dis osal S stems &Under ound Utilities
The subsurface sewage disposal system to serve this dwelling shall be located greater
than 50' from the wetland boundary, as required by Title 5. Due to unsuitable soil
conditions on the northerly side of the wetland swale, the proposed leaching system must
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be located near the road, approximately 200' from the dwelling. This was the only
location on the parcel which would meet the minimum requirements of Title 5. Several
test pits were excavated within the main portion of the lot north of the wetland, but all
pits exhibited dense glacial till with a shallow, perched water table. Pits excavated at the
southeasterly corner of the parcel found a sufficient depth of coarse sand and gravel and a
seasonal high water table at a depth of 70", which will allow a leaching system to be
installed which meets Title 5 requirements. However, in order to meet the setback
requirements to the wetland, an easement onto the Maple Ridge Home Owners
Association buffer strip land is required, as shown on the Site Plan. Preliminary
discussions with representatives of the association have been favorable, pending approval
by the municipal agencies involved (Conservation Commission and Board of Health).
In order to reach the leaching system, a 4" PVC gravity sewer must be installed from the
proposed 1500 gallon septic tank, to be located near the house site. The gravity sewer
will follow the proposed driveway and cross over the existing 12" RCP culvert
approximately 30" above the top of the culvert. This 4" gravity sewer will be heavy duty
PVC (SDR 35) and will have watertight, rubber ring joints to prevent any leakage as it
passes near the wetland. Except for one section which crosses under the driveway, it
shall be laid beyond the edge of the driveway to protect it from traffic loads. The section
crossing under the driveway will utilize a heavier grade of PVC (Sch.40) or cast iron.
The 1500 gallon septic tank shall also be located more than 50' from the wetland
boundary.
The City of Northampton requires a setback of 75' for septic leaching systems from
wetlands versus the 50' required by Title 5, however, there is no feasible location on this
Parcel where we can meet the 75' setback requirement. The Northampton Board of
Health and Conservation Commission must both approve this reduction in setback of the
local regulations back to the Title 5 standard of 50'. A formal septic system design and
application has been submitted to the Board of Heath for their consideration.
Other underground utilities to be installed within the 100' Buffer Zone will be a water
service and electric, telephone, and cable TV. These lines shall run parallel with the
driveway and over the existing culvert.
4. Filling, Dredging and Excavating
No wetland area shall be altered under this proposal. Excavation and grading shall be
limited to the 100' Buffer Zone, as shown on the Site Plan.
The grade of the existing driveway at the 12" RCP culvert must be raised by
approximately 18" in order to provide sufficient cover over the proposed 4" gravity
sewer. The proposed finished side slopes shall be at no greater than a 2:1 slope. The
existing side slopes are poorly vegetated and do not contain a sufficient amount of top
soil to sustain an adequate vegetative cover. To correct this problem, the side slopes
nearest to the culvert inlet and outlet and above the wetland boundary will be re -graded,
loamed, and seeded.
Most of the trees and shrubs nearest to the culvert have grown in wild and are in poor
condition. Many have been damaged by the severe snow and wind storms over the past
two years. It is proposed that the existing vegetation along the proposed driveway be
selectively pruned and replaced with heathy native species, both shrubs and saplings.
5. Compensatory Storage Areas
This project does not involve the filling of any land within a Flood Zone (see Figure 3).
6. Restoration and Replication Areas
No restoration or replacement of wetland is required or proposed under this submittal.
PART IV: MITIGATING MEASURES
1. Inland Bordering Vegetated Wetland
The resource area shall be protected by the installation of a geotextile siltation barrier
installed as shown on the Site Plan. This siltation barrier shall also act as a Limit of
Work line. After the driveway side slopes are loamed and seeded, hay mulch will be
spread over the area to help prevent erosion.
2. Inland Land Subject to Flooding
No Land Subject to Flooding shall be altered under this submittal.
3. 100 -Foot Buffer Zone of Bordering Vegetated Wetland
Protection of the wetland areas adjacent to the construction site will be accomplished by
the use of mandatory setback limits, erosion control barriers, and construction sequences.
Once installed, the siltation barrier shall be considered the no disturbance limit. The
siltation barrier/limit of work line shall be maintained until on-site soils are stabilized.
Any stockpile of soil on the site will be located as far from the wetland as possible.