January 27, 2010

Glenda L. Dean, Chief, NPDES Permit Branch, Water Division
Lynn Broadway, Chief, Office of Water Services
Alabama Department of Environmental Management
P.O. Box 301463
1400 Coliseum Boulevard
Montgomery, AL 36110

Thomas McGill, Chief, Stormwater and Non-point Source Section
Michael Mitchell, Stormwater and Non-point Source Section
U.S. Environmental Protection Agency, Region 4
61 Forsyth Street, S.W.
Atlanta, GA 30303

Via U.S. Mail and Electronic Mail: mitchell.michael@epa.gov, gld@adem.state.al.us, and h2omail@adem.state.al.us

Re: Alabama Construction General Permit, ADEM Administrative Code, Chapter 335-6-12

Dear Ms. Dean, Ms. Broadway, Mr. McGill and Mr. Mitchell:

The Cahaba River Society, the Mobile Baykeeper, the Choctawhatchee Riverkeeper, the Southern Environmental Law Center, River Network, the Alabama Rivers Alliance, the Cahaba Riverkeeper, and the Black Warrior Riverkeeper present the following comments in response to ADEM Public Notice 202 – dated December 29, 2009 and partially entitled “Determination to Initiate Rulemaking Relative to ADEM Administrative Code Chapter 335-6-12.”

We are pleased that ADEM has finally decided to revise the Construction General Permit which it promulgated in Chapter 335-6-12 on January 23, 2003 (hereinafter referred to as “the CGP”). Because the Clean Water Act (“CWA”) and federal regulations require the revision of construction general permits every five years, this revision is needed.
 

Several of the groups listed above sent ADEM a comment letter on the CGP on January 31, 2009. That letter is attached to and incorporated into this letter. That letter provides detailed comments on the many ways that the CGP needs to change in order to conform to federal requirements. These needed changes include 1) the adoption of provisions requiring low-impact development stormwater management measures that will reduce post-construction impacts, 2) much improved reporting and enforcement procedures necessary to ensure better compliance, 3) requirements for better and more frequent monitoring, 4) improvements to the Alabama Handbook, and 5) miscellaneous other changes that will make CGP requirements more clear and more effective.

Our additional comments below address 1) the most effective manner in which ADEM may revise the CGP, 2) the manner in which ADEM should incorporate into the CGP the new federal effluent limitation regulations found at 40 CFR part 450 (hereinafter referred to as “the federal C&D rule”), and 3) the manner in which the CGP should acknowledge and reinforce local stormwater obligations promulgated under federal Clean Water Act MS4 Phase I and Phase II permits.

I. The CGP Should be Issued as a General Permit rather than as a Permit-by-Rule, and It should Contain “Reopener” Clauses to Allow Modifications following Major Stormwater Regulations that EPA plans to issue in 2011 and 2012.

We understand that ADEM is considering eliminating Alabama Administrative Code Chapter 335-6-12 and instead revising the current CGP through a general permit process. We encourage ADEM to revise the CGP through a general permit process for the following reasons:

First, we believe a general permit is preferable because it will be easier to modify than a permit-by-rule. EPA plans to revise substantially its own stormwater requirements in the coming years – both through promulgating its own CGP in 2011 and through other federal stormwater regulations to be finalized by November 2012. See http://www.epa.gov/npdes/regulations/fedreg_swmanagement.pdf in which EPA seeks stakeholder input for its proposed “national rulemaking to establish a program to reduce stormwater discharges from new development and redevelopment and make other regulatory improvements to strengthen its stormwater program.”

Given these coming regulations, ADEM’s federally-imposed stormwater management obligations may increase substantially within the next two years. The additional EPA rules and model CGP are expected to address stormwater management practices that will be essential to improving the water quality of Alabama’s impaired streams. These should be applied in Alabama in the short term, rather than after another 5 or more years has elapsed.

For this reason, we not only ask that the Alabama CGP revision be accomplished as a more easily modified general permit, we also ask that the CGP contain specific “reopener” clauses that will specify a modification process to be followed when EPA issues 1) its own CGP, and 2) the national stormwater rules referred to in the federal register notice above. These “reopener” clauses should allow for full public participation.
 

Secondly, as we noted in our attached letter dated January 31, 2009, the current Alabama CGP requires very substantial revision. Rather than trying to revise a permit-by-rule that is already heavily flawed, we believe that promulgating a new general permit will be more efficient for ADEM, as well as more effective for the restoration and protection of Alabama waters.

Finally, we note that most states issue their CGP as a general permit rather than as a permit-by-rule. Those states have found the general permit process to be preferable for the purposes of meeting their CWA obligations and we suggest that ADEM follow their example.
 

II The CGP Should Contain Stronger NTU Requirements than those Promulgated in the Federal C & D Rule.

A. The CGP Should Contain NTU Requirements Lower than 280 for Most Alabama Construction Sites.

The federal C & D rule establishes a daily maximum numeric effluent limit of 280 NTU for all construction sites greater than 10 acres, either contiguously or cumulatively. 40 C.F.R. 450.22(a)(1). Because Alabama building firms have demonstrated that they can meet a limit lower than 280 NTU using passive stormwater best management practices, and because lower limits are necessary to protect Alabama waters, we believe that the Alabama CGP should set stronger NTU requirements than those promulgated in the federal C & D rule.

The authors of this letter are aware of several large Alabama construction sites involving heavy clay soils and steep topography that have successfully managed construction stormwater run-off to achieve numeric effluent limits that are substantially lower than 280 NTU. These lower NTUs have been accomplished through employment of a complete set of passive best management practices including site design and planning, good drainage, project phasing, effective use of mulch and vegetation, and sediment controls including well-designed sedimentation ponds.

The Shops of Grand River outlet mall, under construction in Leeds, Alabama by Daniel Corporation, represents the challenging conditions in Alabama for sediment and erosion control. This is a very large construction site with fine clay soils, surrounded closely on 3 sides by the Cahaba River and a tributary, with steep topography that has required substantial mass grading. Construction was occurring during the record heavy rainfall period in summer through winter 2009. The passive stormwater treatment train, designed by Schoel Engineers with sediment and erosion control by SpreadRite Organics, has generally achieved excellent results. In December the Cahaba River Society observed a portion of the system. The outfall of the main stormwater detention and settling pond exited the pond at 1100 NTU, traveled through a long trench layered with hay, jute mat, and polyacrylamide powder, and exited this treatment at 50 NTU, the discharge level at the receiving stream. According to the contractor, these are the monitored results generally achieved by this process at this site.
 

Another site called The Edge in Troy, Alabama was on a very steep slope with difficult clay soils. Initially, this site had inadequate erosion and sediment control leading to discharge from the site with a turbidity of about 9000 NTU. Subsequently the drainage system was corrected directing runoff to a number of drop inlets protected by silt-saver devices and vegetative cover was established. Despite a poorly designed (or constructed) sedimentation pond, the upstream turbidity after these treatments was around 90 NTU and the downstream turbidity was around 110 NTU.

The contractors on the projects above have demonstrated that it is both practicable and feasible to achieve a numeric effluent limit that is substantially lower than 280 NTU. If the CGP contains a higher effluent limit than these contractors have established as practicable and feasible, then it will effectively be lowering rather than raising the bar regarding stormwater effluent that may be released from Alabama construction sites. The contractors who are already achieving an NTU much lower than 280 won’t be required to do as much as they are currently, while Alabama contractors who have been slow to develop more effective construction stormwater management practices will have no incentive to reduce their stormwater impacts to the maximum extent practicable and feasible.

At a minimum, 280 NTU should be treated as just an interim maximum while ADEM investigates establishing lower effluent turbidity limits for specific watersheds or types of sites. For example, ADEM could establish a set of effluent limits based upon soil types, R factor and site characteristics including site slope and size.

B. The CGP Should Contain NTU Requirements Much Lower than 280 for Alabama Waters that are Impaired or are not Meeting their Designated Uses.

Alabama has many waters that are impaired (those either included on the 303(d) list or for which TMDLs have been developed) or are otherwise not meeting their designated uses as required under the CWA. 40CFR130.7(b)(1-3). A 280 NTU effluent limitation should be prohibited where it is likely to cause further harm to these waters rather than improving their condition as required under the CWA and by adopted TMDL’s. 40CFR122.4(i).

For this reason, we believe that the CGP should provide special protections for these types of waters. Protecting these waters could be achieved through one of two ways.

First, the CGP could simply require individual permits for any construction sites draining to impaired waters, those with TMDL’s, or those that are not meeting their designated uses. 40CFR122.28(b)(3). The appropriate NTU limit necessary to achieve water quality restoration would be determined at that time. Alternatively, the CGP could establish a significantly lower NTU limitation that must be met by all general permittees whose sites drain to these identified waters, with that lower NTU limitation to remain in effect until ADEM, EPA or local jurisdictions establish watershed-based limitations for each relevant stream or waterbody.
 

In “Urban Stormwater Management in the United States,” a report commissioned by EPA in 2008, the National Academy of Sciences recommended watershed-based permitting as an effective way to halt or reverse damage to waterbodies from stormwater runoff. We encourage ADEM to explore ways to implement this alternative both through the CGP and through future regulation.

III The CGP should Explicitly Recognize that Phase I and Phase II Jurisdictions may Impose Additional Stormwater Management Obligations upon Construction Site Operators and should Contain Provisions that Reinforce those MS4 Requirements.

This year, ADEM will be finalizing new MS4 permits for Phase I and Phase II communities. Those permits will contain enhanced requirements for local government stormwater regulation, monitoring and enforcement. The CGP should reinforce this shift to local regulation by requiring construction site operators to demonstrate that they have complied with any relevant MS4 regulations before they may commence construction under a CGP permit. For example, the CGP should require that construction site operators submit a statement of compliance with local regulations or a locally-issued stormwater management permit when they submit their Notice of Registration (“NOR”) and Construction Best Management Practices Plan (“CBMPP).
 

Thank you for moving ahead with the CGP revision and for your attention to these initial comments. We look forward to working with ADEM to establish a CGP that will protect Alabama waters from construction site stormwater runoff. In particular, we are interested in working with ADEM, EPA and stormwater engineers to identify fully protective, achievable NTU limits for Alabama.

Sincerely,