crosspointe pond retrofit 2014

A Fairfax County, VA, publication

Department of Public Works and Environmental Services

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CROSSPOINTE SEC. 15 PD 15A (#0775DP) PROJECT

Contract Number CN13316004Project Number SD-000017-002Task Order No. 22Springfield District

June 5, 2014

CROSSPOINTE SEC. 15 PD 15A (#0775DP) PROJECT

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

Project DetailsCROSSPOINTE SEC. 15 PD 15A (#0775DP) PROJECT

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

Description:

The Crosspointe Sec. 15 PD (#0775DP) project was substantially completed on August 23, 2014. This is an existing SWM facility and it is located adjacent to the intersection of Cross Chase Court and Cross Chase Circle in Fairfax Station. The project pond was retrofitted to provide improved water quality benefits and additional storage. The proposed water quality benefits realized by this project will be the removal of 10.99 lbs./year of total phosphorus, 2.41 lbs./year of total nitrogen and 472.58 lbs./year of total suspended solids.

Project Overview:• Re-graded the facility to lengthen the flow path and maximize the pond volume.• Excavated and constructed three micro-pools at a maximum depth of 18” below the pond bottom.• Extended class I riprap of the existing two inflow structures to the bottom of the micro pools. • Installed a rock weir structure in addition to minor grading to the stream channel that outfalls into

the existing pond. • Replaced the existing gravel trail and extended it to the location shown on the plan.•Restored the site with seed mix, trees will be planted at the end of Sept. 2014.

Project Team:• Stormwater and Planning Division – Charles Smith• Utilities Design and Construction Division - Yousef Rayyan• Utilities Design and Construction Division – Joseph Adzovie• Surveyor - Gregory Harper

CROSSPOINTE SEC. 15 PD 15A (#0775DP) PROJECT

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

Fairfax Station, VA, Tax Map #106-2

Project Site

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

CROSSPOINTE SEC. 15 PD 15A (#0775DP) PROJECT

PRE-EXISTING CONDITIONS

AN EXISTING RISER

CROSSPOINTE SEC. 15 PD 15A (#0775DP) PROJECT

POST CONSTRUCTION

MICRO-POOL NO.1

MICRO-POOL NO.2

MICRO-POOL NO.3

EXTENDING THE RIP-RAP TO THE BOTTOM OF THE MICR-POOL

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

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

CROSSPOINTE SEC. 15 PD 15A (#0775DP) PROJECT

PRE-EXISTING CONDITIONS

15” RCP INFLOWS FROM THE NORTH END OF THE POND

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

CROSSPOINTE SEC. 15 PD 15A (#0775DP) PROJECT

POST CONSTRUCTION15” RCP INFLOWS FROM THE NORTH END OF THE POND

MICRO-POOL NO.3

THE ACCESS ROAD

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

CROSSPOINTE SEC. 15 PD 15A (#0775DP) PROJECT

PRE-EXISTING CONDITIONS OF THE TRAIL

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

CROSSPOINTE SEC. 15 PD 15A (#0775DP) PROJECT

THE NEW TRAIL AFTER REPLACEMENT

CROSSPOINTE SEC. 15 PD 15A (#0775DP) PROJECT

ROCK WEIR STRUCTURE AND THE IMPROVEMNET OF THE EXISTING CHANNEL

A ROCK WEIR STRUCTURE AND MINOR GRADING WERE PROPOSED TO IMPROVE THE STREAM CHANNEL THAT OUTFALLS FROM THE WEST END INTO THE POND

Before After

CROSSPOINTE SEC. 15 PD 15A (#0775DP) PROJECT

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

Additional Information

For additional Information, please call

www.fairfaxcounty.gov/dpwes

Ben Boxer, Public Information Officer703-324-5880, TTY 711

Ben. Ben Boxer, Public Information Officer703-324-5880, TTY 711

Ben. Ben Boxer, Public Information Officer703-324-5880, TTY 711

Ben.Boxer@fairfaxcounty.gov

Irene Haske, Public Information Officer703-324-5500, TTY 711Irene.Haske@fairfaxcounty.gov

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