From an email to Grace:

From: Bill J. Johnston
Sent: Wednesday, March 31, 2010 9:42 AM
To: Dave Hansen
Cc: Phillip J. Roehrs; John E. Fowler; Jason E. Cosby
Subject: RE: Stormwater/ Chesapeake Bay TMDL

Sorry for the response delay but I was actually at a Municipal Stormwater League meeting yesterday discussing this very topic. The effective date of new State Stormwater Regulations (VSMP) has been delayed pending the Development of the performance criteria needed to meet the Chesapeake Bay TMDL. USEPA is leading the Bay TMDL effort and there have been no hard numbers to date. A draft is expected this summer with a final TMDL to be Issued to the Bay states in December of 2010. I have been closely tracking the development of the Bay TMDL and I was also on the Technical Advisory Committee for the VSMP regulation Changes. I would be happy to present the current status of these regulations to the SDCC when you feel it is beneficial.

William J. Johnston, P.E.
V.P.D.E.S. Permit Administrator
Department Of Public Works, Engineering
Building 2, Room 345
Virginia Beach, VA 23456
Office 757-385-4519
Mobile 757-352-8373

Update:

From EPA’s Chesapeake Bay’ TMDL Section:

Q. What is a TMDL?
A. TMDL stands for Total Maximum Daily Load. The TMDL represents the maximum amount of a pollutant that a body of water may receive and still meet its water quality standards, with a margin of safety. Pollutants are anything that prevents a waterbody from attaining the national goal of being “fishable and swimmable.” The “loadings” are allocated to sources contributing to the problem. A TMDL is comprised of wasteload allocations for “point sources” like sewage treatment plants, urban stormwater systems and large animal feeding operations, load allocations for non-point sources such as polluted rainfall runoff from agricultural lands and impervious surfaces, and a margin of safety.