Public Notice of Missouri’s Construction and Land Disturbance Stormwater General Permit – MO-RA0000

Amanda Sappington
asappington@environmentalworks.com
(573) 619-5757

Missouri’s National Pollutant Discharge Elimination System (NPDES) general permit for stormwater discharges from construction and land disturbance activities will expire on February 7, 2017. In accordance with Missouri Clean Water Law and the Federal Clean Water Act draft permits must be made available for a thirty-day public comment period. Throughout 2016, the Missouri Department of Natural Resources (Department) has conducted meetings and provided drafts to permittees and stakeholders for review. On September 2, 2016, the Department initiated the final phase of the public participation process by placing a draft permit on public notice. If you were unable to participate earlier this year, do not miss your last opportunity to comment now. The proposed permit generally resembles the current permit, which was issued February 8, 2012; however, a few changes to the permit are being proposed.

Notable changes include the removal of the 2.5 ml/L/hr settleable solids numeric effluent limitation. Throughout the past five years permittees have demonstrated that this limit is neither appropriate nor achievable in areas of the state with soil types that are high in clay content. This follows a similar correction by the Environmental Protection Agency (EPA) who also proposed and eventually rescinded a numeric turbidity limit for construction sites. In place of an effluent limitation, the proposed permit contains more prescriptive best management practice (BMP) requirements. Specific new BMP requirements include:

• Install and maintain perimeter controls
• Minimize sediment trackout
• Capture and treat the 2-yr, 24 hour storm event
• Direct stormwater to vegetated areas

The proposed permit also removes the specification that sediment basins on sites ≥10 acres provide storage for 3,600 cubic feet per acre drained. The proposed permit relies solely on the 2-yr, 24 hour storm event as the design criterion for all sites and BMP types, including sediment basins on sites ≥10 acres. This design criterion is specified throughout the permit.

Another significant change for site design is an expansion of the surface water buffer zone from 25 feet to 50 feet. Permittees are required to preserve existing vegetation for at least 50 feet around streams and lakes that lie within or immediately adjacent to the site. Where this is not feasible, alternative designs may be implemented as long as they are equally effective.

The permit on public notice also proposes new flexibility options for inspection frequency that mirror the EPA’s proposed 2017 construction general permit. The new condition allows you to retain the existing seven calendar day inspection schedule or transition to a 14 day inspection schedule, if you can also conduct inspections within 24 hours of any rain event totaling 0.25 inches or more.

Development and implementation of a Stormwater Pollution Prevention Plan (SWPPP) for your site remains the critical step for compliance with the permit and protection of water quality resources. The proposed permit does clarify that a readily available electronic copy of the SWPPP is acceptable in place of a paper copy on the construction site. This change is consistent with the state and federal transition to electronic file management.

Additional regulatory references related to applicability and exemptions are updated throughout the permit for clarity. The draft permit and instructions for submitting comments are available on the Department’s website at https://dnr.mo.gov/env/wpp/permits/pn/docs/RA00000.pdf. Your input is critical to ensuring successful implementation of the permit for the next five-year term, so take a few minutes to review the draft and provide feedback to the regulators while you can. The public comment period ends October 3, 2016.

After public comment, the final permit will be available on the Department’s website for 45 days leading up to issuance of a new permit. The current permit specifies that you must apply for a new permit 180 days prior to the expiration of the permit (February 7, 2017). Things have been changing quickly since that permit requirement was issued and it no longer fits the way the Department does business. During the 2012 renewal of this general permit, the Department rolled out ePermitting applications and has worked since then to ensure successful implementation of this program.

One limitation of ePermitting that has recently come to light is the inability of the database to issue a new permit prior to the permit’s effective date. The proposed permit clarifies the work-around that will be implemented to ensure timely issuance of new permits for ongoing projects. Permittees cannot apply for a new permit until February 8, 2017. The Department is allowing a 60 day grace period, after the permit expires, for ongoing projects to apply for a new permit. During that time, all BMPs must continue to be implemented at your site. If you try to apply early you may pay for, and receive, a permit that is set to expire in February. You must apply for a new permit between February 8 and April 8, 2017. If you do not apply for a new permit within 60 days, the old permit will automatically terminate. Additional information and ePermit applications are available at https://dnr.mo.gov/env/wpp/epermit/help.htm