retrofit facility dp0625 west potomac high school

A Fairfax County, VA, publication

Department of Public Works and Environmental ServicesWorking for You!

Retrofit Facility DP0625 West Potomac High School

November 27, 2017

Contract No. CN15125135Task Order No.1 Project No. SD-000031-143Mt Vernon District

Retrofit Facility DP0625 West Potomac High School

Capital Facilities/Utilities Design and Construction Division/Transportation and Stormwater Construction Branch

Project Details

Description:The West Potomac HS pond retrofit project was substantially completed on October 5, 2017. The overall project consisted of two 18 inch deep forebays; extended detention wetland with depths up to 18 inches; an 18 inch deep micro pool; and a new riser structure which serves to improve the quality of water discharged from the pond. Purpose of this design is to extend the flowpath through the pond to the maximum extent possible and improve the storage volume of the pond. Improvements will increase the residence time of water in the pond and provide enhanced water quality benefits.

Project Overview:• Regraded the facility to lengthen the flow path and maximize pond volume• Excavated and constructed micro-pool to maximize ponding depth of 18”• Installed two curb inlets to capture stormwater runoff from school parking lot• Removed existing headwall and replaced with a new riser structure with a concrete apron and reverse slope trash rack• Restored the site with selective seed mix and native plantings

Retrofit Facility DP0625 West Potomac High School

Capital Facilities/Utilities Design and Construction Division/Transportation and Stormwater Construction Branch

Benefits: • Total Nitrogen Reduction (TN) – 76.30 lb/yr• Total Phosphorus Reduction (TP) – 13.19 lb/yr• Total Suspended Solids Reduction (TSS) – 12,416.43 lb/yr

Project Team:• Stormwater Planning Division – David Anglin, Kenneth Trinh• Utilities Design and Construction Division (UDCD) – Christopher Triolo, Alan Rashid• Project Inspector, UDCD – Jeff Bartlett, James Beachum• Bowman Consulting, Design Consultant- Roy Waugh, Steven Liam, Camilo Apolinares• Contractors: PITT Construction, Inc. and Ashburn Contracting Corporation

Retrofit Facility PD0625 West Potomac High School

Capital Facilities/Utilities Design and Construction Division/Transportation and Stormwater Construction Branch

Mt Vernon District, Tax Map No. 93-1 ((01)) 0054

Retrofit Facility PD0625 West Potomac High School

Capital Facilities/Utilities Design and Construction Division/Transportation and Stormwater Construction Branch

New Pavement & Drainage Swale – Stokes Lane

Retrofit Facility PD0625 West Potomac High School

Capital Facilities/Utilities Design and Construction Division/Transportation and Stormwater Construction Branch

Completed Project

Before After

Retrofit Facility PD0625 West Potomac High School

Capital Facilities/Utilities Design and Construction Division/Transportation and Stormwater Construction Branch

Additional Information

For additional Information, please call

www.fairfaxcounty.gov/dpwes

Retrofit Facility DP0625 West Potomac High School

Capital Facilities/Utilities Design and Construction Division/Transportation and Stormwater Construction Branch

Matthew Kaiser, Public Information Officer703-324-8455, TTY 711

Matthew.kaiser@fairfaxcounty.gov