Saturday, April 4, 2009

Oil - Gas - Refining Sector - SWPPP - Stormwater Permit Proposed Requirements

On July 6, 2009, the Minnesota Pollution Control Agency released its proposed multisector industrial stormwater discharge general permit. This permit, once promulgated, will replace the existing industrial stormwater permit, which expired in October of 2002.

[Read a summary of the overall Minnesota permit, stormwater monitoring, and sector requirements]

Caltha LLP will be conducted seminars on the proposed sector requirements in July & August 2009. Caltha MPCA Industrial Stormwater Permit Requirements Seminars

The proposed permit details requirements for 29 different industrial sectors. The requirements described below are proposed for the Oil and Gas Extraction and Refining Sector (Sector I). Sector I covers a fairly broad range of facility types, including crude petroleum and natural gas, natural gas liquids, oil and gas field services, drilling oil and gas wells, and petroleum refining. These requirements are in addition to permit requirements that apply to all sectors.

The facility must conduct inspections addressing equipment and vehicles that store, mix, or transport chemicals or hazardous materials.

In addition to routine inspection requirements, the operation must conduct two of the monthly inspections during runoff events. One of the inspections must be performed during a snow melt runoff event. Each inspection must include a visual assessment of the runoff to identify any visible sheens or films that indicate the presence of oil or grease in the discharge.

Preventive Maintenance:
The pollution prevention program must implement measures that prevent or minimize contamination of stormwater from chemical mixing areas, and take measures necessary to prevent discharge of stormwater coming into contact with wastewater pollutants from any sources associated with production, field exploration, drilling, well completion, or well treatment.

Potential Pollutant Sources:
The pollution prevention program must describe the following sources that have pollution potential: chemical, cement, mud, or gel mixing activities; drilling or mining activities; equipment rehabilitation activities. In addition the SWPPP must include information about the RQ release that triggered the permit application requirements: the nature of the release, amount of oil or hazardous substance released, amount of substance recovered, date of the release, cause of the release, areas affected by the release, procedure to clean up release, actions or procedures implemented to prevent or improve response to a release, and remaining potential contamination of stormwater from release.

Stormwater Monitoring Benchmarks:
All facilities are required to conduct visual and chemical (benchmark) monitoring. For benchmark monitoring, the benchmark concentrations or values depend on product type:

Oil and Gas Extraction (SIC 1311, 1321, 1381-1389):
TSS 100 mg/L
pH 6-9

Oil Refining (SIC 2911):
Ammonia 34.8 mg/L
Total Zinc 0.234 mg/L

Note: Benchmarks for zinc and ammonia were derived based on the Aquatic Life Standards for these parameters in Minnesota Rules.

[Read more about use of Aquatic Life Standards to derive stormwater benchmarks]
[Read more about how benchmarks are used under the proposed MPCA industrial permit]
[Read more about what a 100 mg/L benchmark for TSS relates to]

Looking for other sector information? Click here for a link to all sector requirements

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address Stormwater Permitting & Regulatory Support, Stormwater Pollution Prevention Plans (SWPPP), Stormwater Monitoring and Stormwater Training.

For further information contact Caltha LLP at
Caltha LLP Website

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