swppp.pdf

NIAGARA FALLS AIR RESERVE STATION

NIAGARA COUNTY, NEW YORK

WATER DISTRIBUTION SYSTEM

REVITALIZATION

STORM WATER POLLUTION PREVENTION PLAN

February 2004

WATER REVITALIZATION SYSTEM 94-0466

1.0 Introduction

The Niagara Falls Air Reserve Station is located within the Town’s of Niagara and Wheatfield in Niagara County New York. The Base is the home to 914th AirLift Wing and the 107th Air National Guard. The Air Reserve Command (ARC) owns and operates a water transmission and distribution system, which provides domestic water service and fire flows to about fifty-five buildings on base as well as the supply to the Air National Guard (ANG) Distribution System. The water system is approximately fifty years old.

Due to the age of the facilities and the increasing failures of the system, Base Engineering has retained the services of Urban Engineers of New York, P.C. and Trautman Associates to study and design a Water Distribution System Revitalization.

1.1 Stormwater Management Objectives

The objectives of this Stormwater Pollution Prevention Plan (SWPPP) are identified as follows:

• Provide a Sediment and Erosion Control Plan to minimize the impact of construction activities on the existing downstream stormwater quality,

• Emphasize construction practices which focus on source control of stormwater pollution,

• Implement Best Management Practices (BMP’s) to protect existing streams running within and downstream of the air base,

• Provide maintenance of stormwater controls during and after construction completion.

This plan has been developed in accordance with Air Force Instruction (AFI) 32-7041, the New York State Standards and Specifications for Erosion and Sediment Control and the New York State Stormwater Management Design Manual (NYSSMDM).

1.2 Pre-Development Conditions

A site location map based USGS quad map information is included as Figure 1. The existing conditions of the project area includes a well developed Military Base with approximately 55 buildings, Runway and taxiway facilities, Roads, and related infrastructure (water, sanitary sewer, storm, communications, etc.)

2.0 Proposed Project

The proposed project includes the replacement of the entire ARS water distribution system including watermain, hydrants, valves, services and related construction items.

The project will be located throughout the base and continue southerly to building 729 which is the primary feed from the Niagara Falls water supply. A map identifying the work areas is attached as Figure 1.

The estimated length of new watermain to be constructed is summarized as follows:

Diameter Length (Feet)

12” 9,800 10” 7,900 8” 9,900 6” 700 Sub-Total 28,300 Services:

4” 470 3” 700 2.5” 170 2” 960 1.5” 650 1” 1,500 ¾” 150 Sub-Total 4,600

TOTAL 32,900

Additionally, an estimated 59 hydrants will be removed and replaced and 160 new main valves and service valves will be constructed. All ground disturbance will be repaired in-kind with the pre-construction conditions. A detail of the typical trench excavation is attached as Figure 2.

The estimated cost of construction for this project is $1,995,000.

The total disturbance associated with the project will be limited to the excavated areas and immediate surroundings. For the purpose of this plan, we estimate the disturbed corridor to be a 10-foot wide strip along the main line corridor and a five-foot wide strip along the service installations. Therefore, the total disturbed area is estimated to be 7.1 acres. The actual area of excavation is approximately 2.3 acres.

3.0 Soils

A review of the Niagara County Soils Survey, as assembled by the United States Department of Agriculture, Soils Conservation Service shows that the predominate soil type on the base is Odessa silty clay loam. This soil type tends to have a high clay content limiting permeability. The soil tends to be hard when dry and sticky when wet.

Erosion and Sediment Control measures should be designed to protect against runoff with low percolation and good housekeeping measures should be enforced especially when the soil is wet.

4.0 Drainage Patterns

Currently the base utilizes a storm sewer network that utilizes both piping and open channels to collect storm water from the base and discharge to Cayuga Creek, which runs along the southern boundary of the base. The proposed project will not change any grades or drainage patterns. The project will not increase the total impervious areas on the base.

In accordance with the NYSSMDM, the Unified Stormwater Sizing Criteria is described as follows:

Water Quality: The Water Quality Volume is directly related to the amount of impervious cover created at a site. Since this project will not increase the amount of impervious cover, no Water Quality controls will be required.

Channel Protection, Overbank Flood and Extreme Storm: This project will not change the existing grades and will not increase the amount of impervious area. As such, the pre-development and post-development runoff volumes will be equal under the 1-year, 24-hour storm event, 10-year storm event and 100-year storm event. As a result, no new water quantity controls will be required to protect against these conditions. Generally, the downstream receiving waters will not see changes in water quality or quantity as a result of this project.

As per the New York Department of Environmental Conservation, the section of Cayuga Creek in the vicinity of the base is class C unprotected stream.

5.0 Erosion and Sediment Control

E&S controls include but are not limited to: Soil stabilization, vegetated buffers, storm drain inlet protection, stream diversion, good housekeeping, dust control, spill prevention and control. Best Management Practices (BMP) fact sheets for these measures as prepared by the United States Environmental Protection Agency (EPA) are included in Appendix A. (Note: Refer to United States Environmental Protection Agency website for Construction Site Storm Water Runoff Control Data sheets.)

• Soil disturbance should be kept to a minimum at all times during construction.

Equipment bucket widths should not be larger than is required to dig a sufficient trench in accordance with the contract documents. Any material to be used as backfill should be sidecast as close as practicable to the trench. Excavated material which will not be used as backfill shall be removed from the base as it is excavated.

• As soon as possible after trench excavation and backfill, rough grading of the disturbed soil shall be performed and the contractor shall seed and mulch the area of disturbance to stabilize the soils. The contract documents will require rough grading and seeding throughout construction without allowing any more than 1,000 linear feet of trench to be disturbed prior to grading/seeding. Appendix A includes EPA guidelines for the BMP’s of Seeding and Mulching.

• Existing vegetated areas between the proposed trench and existing stormwater infrastructure shall be maintained to act as vegetated buffers. EPA guidelines for use of vegetated buffers as a BMP are included in Appendix A.

• Wherever the trench excavation lies within 10 feet of a storm sewer drain inlet, Storm

Drain Inlet Protection should be used. The protection shall include a filter fabric material and be constructed and approved in advance of the trench excavation. An EPA guideline regarding the construction of the devices is included within Appendix A.

• Trench dewatering (if required) typically involves the removal of water with high sediments. None of this water should be directly discharged into storm sewers. The use of filter strips or sediment traps will be required for trench dewatering.

• Watermain disinfection involves the use of heavily chlorinated water. Chlorinated water shall not be discharged directly into the storm sewer under any condition.

Wastewater from disinfection shall be neutralized and discarded into the storm or sanitary sewer in accordance with AWWA standards for watermain disinfection.

• The proposed construction involves the crossing of Cayuga Creek once and tributaries to Cayuga Creek three times. During construction of these crossings, the Contractor will be responsible to provide a stream diversion control (cofferdam, sluice pipe, etc.) until the streambed is stabilized. A sample sluice pipe stream diversion detail is shown on Figure 3 following this page.

• Standard “Good Housekeeping” practices should be used to provide waste collection areas with covered receptacles, control site dust concerns and minimize chemical and fuel spillage potential. Proper waste management practices will prevent packaging, labels and other trash from ending up in the receiving waters. Responsible practices for minimizing and control of fuel/chemical spills will also protect the receiving waters. The EPA BMP guidelines for Construction site waste management and spill prevention and control should be followed at all times and are further described in Appendix A.

• The creation of dust not only presents a nuisance condition, but also contributes to sedimentation and water pollution as well as posing risks to environmental and human health. The contractor should make every effort to control dust by performing the following: Strict adherence to soil stabilization measures, minimize use of equipment and trucking operations in disturbed areas, use sprinkling/irrigation to reduce amount of dust, and keep driving areas as clean as possible. The EPA BMP description is included in Appendix A.

6.0 Water Quality and Water Quantity Control

Permanent storm water Quality and quantity controls are not required as part of this project.

7.0 Schedule

Prior to construction, the contractor shall provide a schedule of activities required to meet this SWPPP to the base engineer. Measures required prior to trench excavation, such as inlet protection and creek diversions should be installed 48 hours prior to construction in that vicinity. Other items such as soil stabilization, vegetated buffers, trench dewatering, good housekeeping and dust control should be exercised continuously throughout construction activities.

The contractor shall provide a weekly written report of all Erosion and Sediment control activities to the Base Engineer. A certification form for Erosion and Sediment Control measures is included as Appendix B. This certification shall be completed at a minimum of seven days or within 24 hours of a rainfall event of 0.5 inches or more.

APPENDIX A

Refer to the United States Environmental Protection Agency for Construction Site Storm Water Runoff

Control data sheets

APPENDIX B

Refer to attached Sample Inspection Report Form

SWP3-E&S #3