Chesapeake Stormwater Network Latest News

Mosquitos and Bioswales

CSN — Wed, 09 Dec 2009 03:01:05 +0000

This is a report on mosquito breeding in bioswales in Delaware that Randy Greer of DNREC passed along to me recently. It offers some troubling data on potential mosquito production from these areas, and some prevention techniques.

Bioretention Hydrology

CSN — Wed, 09 Dec 2009 02:59:59 +0000

A recent paper on bioretention hydrologic performance provides reliable data on how runoff reduction actually works within test bioretention cells. This solid paper also provides technical support for many of the Level 1 and 2 design criteria that are being proposed in the Commonwealth of Virginia.

Maryland Bioretention

CSN — Wed, 09 Dec 2009 02:57:35 +0000

You can never read too many papers on bioretention. This 2008 offering by Dr. Allan Davis at University of Maryland provides an excellent summary of the hydrologic performance of two test bioretention areas, based on monitoring of many, many storms. Click here.

Talking Trash in Runoff

CSN — Wed, 09 Dec 2009 02:52:23 +0000

The last paper is a notable contribution from our fellow Australian stormwater geeks that looks at "gross pollutants" in stormwater – things like trash, debris, floatables and the like. We are often so nutri-centric in the Bay watershed that we often overlook the massive loads of these pollutants. Not so our fellow citizens, who are astonished by the trashiness of urban stormwater while walking along the Baltimore or Anacostia waterfront. Click here to learn more about urban grossness.

Industrial Stormwater Compliance

CSN — Wed, 09 Dec 2009 02:49:00 +0000

This report details how California assessed compliance levels at thousands of stormwater hotspots across many different industrial sectors. The report, prepared by Tetra- tech, chronicles the spotty compliance record at most industrial NPDES stormwater sites, but also documents on how it markedly improved after site audits, inspections and technical assistance were applied. Since we don't do such a great job in inspecting stormwater hotspots in the Bay watershed, folks may want to click here to find out ways to improve our game.

Phosphorus Fertilizer Bans Work in Minnesota

CSN — Wed, 09 Dec 2009 02:34:47 +0000

Product substitution is one of the most effective stormwater pollution control tools that we have, but we rarely wield it. Think for a minute about the dramatic reductions in lead concentrations in stormwater runoff that were achieved by the introduction of unleaded gasoline.

LID Subdivision Monitoring

CSN — Wed, 09 Dec 2009 02:15:17 +0000

A paper by Bill Selbig and his colleagues in Wisconsin summarizes a six-year paired monitoring study of a traditional subdivision versus a subdivision that was designed with LID practices. The results indicate a significantly different hydrological response from the LID subdivision. Click here for a copy.

Jordan Cove LID Monitoring Study

CSN — Wed, 09 Dec 2009 02:14:09 +0000

This long-awaited paper summarizes one of the nation’s longest running LID research sites, the Jordan Cove Study. This updated review of the results of this landmark monitoring study can be accessed here.

LID Costs for Redevelopment Sites

CSN — Wed, 09 Dec 2009 02:13:00 +0000

This 2008 report released by the Chesapeake Bay Foundation looks at the feasibility of Low-Impact Development practices using three real world urban redevelopment project sites in Maryland. Modeling showed that these practices enabled dense urban mixed-use redevelopment projects in Maryland to capture and filter/ infiltrate substantial volumes of stormwater at reasonable costs when compared with conventional (non-green) solutions such as underground storage tanks. This is an important finding as Bay states struggle to define more stringent stormwater requirements for redevelopment projects. To get a copy of their study and modeling assumptions click here.

President Obama’s Executive Order: Stormwater Recommendations

CSN — Tue, 08 Dec 2009 00:58:30 +0000

President Obama issued an Executive Order 13508 last May to accelerate progress made to restore the Bay. The order called for EPA to report on the next generation of tools and actions to restore the Bay using existing regulatory authorities. The first reports were released in early September, and two of them focus heavily on stormwater.