The U.S. Environmental Protection Agency has proposed that construction companies use best management practices in lieu of measuring numeric turbidity limits to address stormwater runoff and to prevent erosion at construction sites. The significance of this proposed change is that it replaces testing requirements with management practices.

In the proposal, Effluent Limitations Guidelines and Standards for the Construction and Development Point Source Category, 78 FR 19434 (April 1, 2013), EPA said it will no longer require builders and engineers to monitor turbidity in stormwater runoff and will withdraw numeric turbidity limits imposed in 2009.

The new limits emphasize best management practices (BMPs) proposed under a settlement agreement that EPA reached with builders and utilities to resolve a lawsuit over the 2009 stormwater rule (Wisconsin Builders Ass'n v. EPA, No. 09-4113 (7th Cir., Dec. 21, 2012)).

In summary, the proposed revisions to 40 CFR part 450 consist of the following three elements:

  • Addition of a definition of “infeasible” consistent with the preamble to the 2009 final rule, and the 2012 Construction General Permit. Under the proposed rule “infeasible” means “not technologically possible, or not practicable and achievable in light of best industry practices”.
  • Revisions to various effluent limitations and new source performance standards (NSPS) found at 40 CFR 450.21, 450.22, 450.23, and 450.24.
  • Withdrawing the numeric turbidity effluent limitation and monitoring requirements found at 40 CFR 450.22(a) and 450.22(b), and reserving these subparts.

With respect to the regulatory revisions, changes to these standards include clarification of “erosion”. Under the new proposal permittes must:

  1. Control stormwater volume and velocity to minimize soil errosion in order to minimize pollutant discharges;
  2. Control stormwater (including peak flow rates and total stormwater volume) to minimize chanel and streambank erosion;
  3. Provide and maintain natural buffers, direct water to vegetated areas, and maximize stormwater infiltration;
  4. Minimize soil compaction; P
  5. reserve topsoil, and stabilize distrubed areas immediately whenever clearing, grading, or ecavating have permanently ceased or will not resume for fourteen days (with limited exceptions); and
  6. Minimize stormwater exposure to building materials and products, construction waste and trash, landscaping materials, and to chemicals including fertilizers, pesticides, herbicides, and detergents (subject to limited exemptions).

Comments on the new proposal will be accepted through May 31, 2013.