POST CONSTRUCTION STORMWATER MANAGEMENT FOR "WHITE OAK SEWER INTERCEPTOR"

Transcription

1 POST CONSTRUCTION STORMWATER MANAGEMENT PLAN FOR "WHITE OAK SEWER INTERCEPTOR" Located in Newberry Township, York County March 21, 2008 Prepared by: Mellott Engineering, Inc Devonshire Heights Road Hummelstown, PA (717)

2 TABLE OF CONTENTS AERIAL LOCATION/SEWER INDEX MAP USGS LOCATION MAP SOILS MAP PROJECT DESCRIPTION EXISTING PHYSICAL FEATURES BEST MANAGEMENT PRACTICES (BMPs) SUMMARY

3 ~ \'. 1~,.~ \ i' i... r r,;' "" 1 ~/" ". Stream C~nQ'4 (FishingCre~k.,a j perennial stiep~) fit'.,~v. \\.1. ",. s~ Crossing#2 (Intermittent stream, dry bed unless raining)..,. Existing Fox Farm 'nterl~r (DoWnstream limit of project~..( ~..,.,.f'

4 Name: STEEL TON Date: 11/12/2007 Scale: 1 inch equals 2000 feet Location: ' 33.72" N ' 26.48" W Caption: White Oak Sewer Interceptor Newberry Township, York ~.33"" u f ",,::>.Ie. 2> o,,~.{ Copyright (C) 2001, Maplech. Inc.

5 Sol/Map D SoDs Roads II /'/' /'/' IntelSlate us Route Slate Route Local Roads./'/' AccessRamps Other D Water StreamsText Streams /" Other ", Intermittent /oit' /"', Perennial Counties Townships Text Townships /'" Boroughs o Wetlands Map Scale 1:10392, 1 inch =866 feet Created by SoilMap, 11/12/20079:13:42 PM The Infonnation on SoilMap is provided 'as is' and the User assumes the entire risk as to its quality and perfonnance. Soil maps are subject to change and may be copied without pennlssion. Enlarging the maps may cause misunderstanding of the detail of mapping. Help in using soli surveys is a White Oak Sewer Interceptor Project ~vailablefromthe localofficeof the NRCS. ~ W N Geospatlal Technology Program E

6 PROJECT DESCRIPTION The "White Oak Sewer Interceptor Project" is a sewer improvements project proposed in Newberry Township, York County. The project consists of the abandonment of the existing White Oak Pump Station and the installation of approximately 10,504 LF of 18" gravity sewer. The upstream limitof the project starts at the White Oak Sewerage Pump Station located at the White Oak Township Park and extends down stream along the Fishing Creek corridor and connects into the an existing public gravity sanitary sewer system just off of Pines Road (see Location Map on sheet 2 of this report for a location map and project delineation). The project area encompasses approximately 13.5 acres with a conservatively estimated disturbance area of 12.0 acres. The entire temporary construction easement shown on this plan was conservatively estimated to be disturbance area although a good portion of this area is not anticipated to be disturbed (stone stock piling and pipe storage areas). Neither development nor impervious coverage is proposed with this project (sewer installation only). The disturbed areas willbe restored to existing grades and shall be stabilized with a vegetative cover (permanent seeding). EXISTING PHYSICAL FEATURES See the drawings for existing topography and mapped soils. The project area is composed of maintained yard areas, brush areas, woodlands and agriculture coverage (meadow). The entire project is located within the Fishing Creek (TSF) watershed; see attached USGS Map. Wetlands have been delineated and are shown in different areas of the site. Wetland areas and streams were delineated and classified on the plans. Some onsite wetland pockets and streams will be temporarily disturbed with during construction and will require permitting (General Permits 5, 7 &8). The previous and current use of the project areas are Township Park Land, maintained lawn areas, woodlands and agriculture. Soil types delineated on this site are described as follows by the SCS York County Soil Survey: Suitability of soil for: Soil Series Road fill Topsoil Depth to Depth to Soil Water Bedrock Reaction Table (in) (in) (ph) (KnE) Klinesville channery Poor: slope, depth to Poor: slope, small > silt loam, 25-40% rock stones, dedthto rock (PcF) Penn channery loam, Poor: slope, depth to Poor: slope, small > % rock stones (PeC) Penn silt loam, > Poor: depth to rock Poor: small stones 8-15% (Rw)Rowland silt loam, > Fair: wetness Poor: area reclaim 0-3% Implications and resolutions of the above soil types with proposed development are as follows: In general, the soils present should not pose any significant limitation to the type of development proposed. Reference the following recommendation pertaining to possible issues that may be encountered during construction.. If unrippable rock is encountered during trenching, blasting or drilling may be required. Removed rock can be crushed if necessary and used for backfill (not bedding).

7 . If water table is encountered during excavation, dirty water shall be pumped out into a filter bag or sediment removal pond.. If soil exhibits a high acidity, the addition of lime or other neutralizer to the seed mixture may be required. BEST MANAGEMENT PRACTICES Due to the limited impacts associated with a utility installation project BMPs used for this project consist of the following: 1. Earth disturbance and vegetation removal will be limited to the amount necessary for the sewer installation. 2. All disturbed areas will be restored to the original existing grades. 3. Permanent grass seeding. All disturbed areas shall be seeded with the required permanent seed mixture. The grass coverage shall improve infiltration capabilities as well as provide erosion protection from surface runoff. 4. No impervious coverage is proposed with this project. Existing impervious coverage at the White Oak Pump Station shall be removed with this project and restored to vegetative cover. SUMMARY The projects impact on water quality rate and volume are negligible with the proposed utilization of proper erosion control measures during construction, stabilization of all disturbed areas with a permanent vegetative cover and with the removal of some existing impervious coverage.