Research Alert: Are Wet Pond or Wetland Sediments Toxic?

The short answer is no, according to a recent study by Jackie McNett and Dr. Bill Hunt of North Carolina State. They tested sediments excavated from the forebays of 30 wet ponds and wetlands across the state, and found that all of them could meet EPA standards for land application of biosolids.

Slightly over half the samples did exceed EPA sediment guidelines for aquatic life. These findings suggest that it is generally safe for the land to apply sediments from pond cleanouts, and it may be wise to do it more frequently to protect aquatic life within the pond.

For more details on the study, led by McNett and Hunt of NCS, view the full report: An Evaluation of the Toxicity of Accumulated Sediments in Forebays of Stormwater Wetlands and Wetponds.

New Release - Technical Bulletin No 9

Many Bay states and localities are struggling with how to analyze which combination of urban stormwater practices can most cost-effectively meet their target nutrient load reductions under the Chesapeake Bay TMDL.

To meet this need, CSN has just released a draft technical bulletin for external peer review. Technical Bulletin No. 9 synthesizes existing research on nutrients in stormwater and the performance different stormwater BMPs in removing them.

The bulletin also proposes interim removal rates for more than a dozen urban BMPs, and outlines simple computational methods to do nutrient accounting. Most importantly, the Bulletin outlines a 12 step process to find your easiest and cheapest opportunities to earn local nutrient reduction credits.

The Bulletin is open for comment until October 15, and we encourage stormwater managers at all levels of government to send in your comments to watershedguy@hotmail.com.

You can download this new release here: Technical Bulletin No. 9

Low Impact Development Symposium in Philadelphia

The Philadelphia Low Impact Development Symposium will bring in stormwater experts from all over the nation on September 25-28.

"I strongly recommend that you take the train to Philadelphia and take in a day or two of this national confab of LID experts and researchers" Tom Schuleur of CSN says, "I’m a notorious conference cheapskate, but the agenda for this one is so good, that I will be there myself."

To access the agenda and get registration details, go to the conference website: http://www.bae.ncsu.edu/stormwater/2011lid/program.html

CSN Joins the EPA Chesapeake Bay Program as Technical Coordinator for Urban Stormwater

As of September 1, Tom Schueler will be working several days a week in Annapolis, Maryland with EPA and its restoration partners to coordinate with local, state and federal stormwater managers to accelerate the implementation of cost effective sediment and nutrient reduction practices for urban and suburban lands across the watershed. Under the six year cooperative agreement, CSN will provide technical coordination and assistance to help stormwater managers achieve their target load allocations under the Chesapeake Bay TMDL. This will entail leading urban BMP review panels, developing improved stormwater cost data, enhancing technical capacity and recommending updates to the Bay Watershed Model and Scenario Builder.

Most of all, CSN intends to expand communication with stormwater stakeholders at all levels of government and the private sector on the most innovative and cost effective ways to treat polluted runoff. Tom will be traveling throughout the Bay this fall to meet with state stormwater agencies to get their input and perspectives.  

Research Alert: Thermal Impacts of Stormwater Practices

A new University of New Hampshire research study investigated the comparative water temperature in stormwater as it passed through a dozen different stormwater practices. Past research has show that some surface stormwater practices such as dry ponds and wet ponds can significantly heat up water, often to levels that are harmful to trout and other aquatic life that inhabit cold-water streams. The new research reinforced that finding for test sites in Durham, New Hampshire. On the positive side, the research team discovered that some stormwater practices were thermally neutral, and could protect cold-water fisheries. These practices all featured sub-surface discharges, such as bioretention, infiltration and submerged gravel wetlands. For more details on the study, led by Dr. Rob Roseen of UNH, view the full report: Examination of Thermal Impacts From Stormwater Best Management Practices.