Tuesday, January 31, 2012

Water gets cleaner beneath your feet at Duck Creek, Wellfleet

Wes Stinson (left) of Environmental Partners Group and Lee Davis, Chair of the Cape Cod Conservation District, hold a floating debris trap that will be installed beneath the street. The trap will catch oil and large debris before they reach sand and fabric filters, also under the street.

By Abigail Franklin, Cape Cod Conservation District and Chloe Wardropper, NRCS conservation intern

One of the most photographed sites on Cape Cod is Uncle Tim’s bridge in Wellfleet. Few people know however that the water quality under this bridge has been affected by the nearby roads and parking lots.  Like many asphalt roads and parking lots near open water, Commercial Street and Holbrook Avenue have been channeling untreated surface water – stormwater – into Duck Creek because of their large impervious surface areas. Stormwater usually carries contaminants such as fertilizer and bacteria that flow directly into surface water if not first caught and filtered.

Fortunately a stormwater treatment project is in progress that will significantly improve the water quality of Duck Creek. Traffic is being affected along Commercial Street between Bank Street and Holbrook Avenue, but the disturbance is only temporary. Soon, cleaner water will be filtering into the saltmarsh thanks to the installation of 12 separate underground containment and purification centers.

Construction crews have been removing pavement in sections and digging holes for catchment and treatment basins since November 2011.  The catchment basins collect untreated stormwater runoff. From there, water flows into connected leach basins where it trickles slowly downward through porous material that removes pollutants. 

Oddly shaped green plastic devices called floating debris traps will be positioned over the discharge pipes leading from the catchment basins into the infiltration systems. Their job is to collect oil and large debris that can impair the function of the sand and filter fabric that treats the contaminated water. The oil, debris and other sediment will be removed when the Town empties the catch basins twice a year.

Duck Creek is a central feature in Wellfleet’s historic downtown, and the stormwater treatment is important to restore water quality, improve wildlife habitat, and to potentially allow shellfish growing and harvesting in the future.  So they next time you walk past a storm grate, think of all the good work that’s being done underneath your feet!

Watch the Duck Creek stormwater project evolve in this video slideshow:

Monday, January 9, 2012

Water quality makeovers in Brewster: Paine’s Creek Landing and Saint’s Landing Beach stormwater projects

Stormwater improvements under construction at Paines Creek Landing, Brewster
By Chloe Wardropper, USDA-NRCS Conservation Intern and Abigail Franklin, Cape Cod Conservation District

Cape Cod’s Town of Brewster recently received a water quality makeover at two important shellfishing and recreation areas.  Until recently, Paine’s Creek Landing and Saints Landing Beach, five minutes apart on Cape Cod Bay, had an unfortunate commonality: they discharged stormwater into the Bay.  Like many asphalt roads and parking lots near open water, the paved surfaces at Paine’s Creek and Saint’s Landing were channeling untreated surface water – stormwater – into an important water body because of their large impervious surface areas. So the Cape Cod Water Resources Restoration Project installed underground systems to catch and treat this stormwater to prevent more harmful contaminants from entering Cape Cod Bay.

What are impervious surfaces?  A surface – such as an asphalt road – is impervious when water cannot seep through it.  A sponge, for instance, is a pervious surface, while a dinner plate is impervious.  When water encounters an impervious surface, it runs downhill until it hits a surface it can sink into.  As it flows, water picks up contaminants such as fertilizer and bacteria.  Wetlands serve as natural water catchments and play the crucial role of filtering out contaminants in water before it seeps back into the groundwater. 

There are many places in developed areas, however, where there are insufficient wetland and other pervious surface areas to absorb periodic high flows of stormwater running off paved roads.  These areas benefit greatly from stormwater runoff treatment systems. 

The treatment systems installed at Paine’s Creek and Saint’s Landing in Brewster are called infiltration systems.  Like the Barley Neck Road project in Orleans, they consist of catchment basins connected to leaching basins.  The catchment basins are placed underground at the bottom of an impervious slope and collect the untreated stormwater runoff.  Water then flows into the leach basins where it trickles slowly downward through porous material that removes pollutants.

At Saint’s Landing, two separate catchments direct water into leach basins installed under the beach parking lot.  And at Paine’s Creek, the Town of Brewster decided that in addition to leach systems they would go one step further in protecting Cape Cod Bay water quality by moving the entire parking lot farther inland.  The new location also addresses beach erosion issues and creates more beach area for residents and visitors. 

Watch video slideshows of the work progressing at these project sites:

A Water Quality Makeover at Paines Creek Landing, Brewster

A Water Quality Makeover at Saints Landing Beach