Before the Rain: A California IGP Permittee’s Storm Season Checklist

For businesses subject to California’s Industrial General Permit (“IGP”), the beginning of the rainy season is a good time to take a fresh look at the facility’s stormwater compliance program.

Many IGP requirements apply throughout the year, but significant rain can expose problems that are easy to overlook during the dry season. Outdoor materials may become exposed to precipitation. Drainage patterns may not work as expected. BMPs may need maintenance or modification. And for facilities that have experienced stormwater monitoring problems in the past, the next significant storm may bring those issues back into focus.

A pre-storm review gives a facility an opportunity to identify and address these issues before they contribute to a problematic discharge or create additional compliance concerns.

Does the SWPPP Still Reflect the Facility?

The first place to look is the facility’s Storm Water Pollution Prevention Plan (“SWPPP”).

The IGP requires covered facilities to develop and implement a site-specific SWPPP addressing, among other things, the facility’s industrial activities, potential pollutant sources, BMPs, and monitoring program. The SWPPP must be revised when necessary to remain consistent with the facility and the permit requirements.

Industrial facilities can change significantly over time. Equipment may be relocated. Production processes may change. New materials may be introduced. Outdoor storage areas may be added or modified. Construction or other improvements may also change how stormwater moves across the property.

Before the rainy season, a facility should compare its current operations and physical layout with its SWPPP and site map. Are the drainage areas still accurate? Are the discharge points correctly identified? Are the industrial activities and potential pollutant sources still the same? Are materials being stored or handled in areas that are not reflected in the SWPPP?

If the facility has changed, the SWPPP may need to change with it.

The issue is not simply whether a facility has a SWPPP. The SWPPP should accurately describe the facility and the measures being used to address potential stormwater pollution.

Are the Facility’s BMPs Ready for Rain?

The IGP requires permittees to implement BMPs to reduce or prevent pollutants in stormwater discharges. Before significant rainfall begins, those BMPs should be inspected and maintained.

That review should include areas where industrial materials or activities may be exposed to stormwater. Depending on the facility, this may include outdoor storage, loading and unloading areas, waste handling areas, equipment and vehicle maintenance areas, and other portions of the property where industrial materials are present.

Facilities should look for conditions that could become problems during a storm. Containers or covers may have deteriorated. Materials may have been moved. Containment areas may require maintenance. Sediment or debris may have accumulated in drainage areas. A BMP that was adequate under one set of operating conditions may no longer be adequate after the facility has changed.

The IGP also requires facilities to evaluate and revise their BMPs when necessary to meet the permit’s requirements. For a facility that has experienced recurring stormwater problems, the start of a new rainy season is therefore a good time to ask whether existing controls are addressing the source of the problem or simply managing its symptoms.

What Did Last Year’s Monitoring Results Show?

Previous monitoring results can provide useful information about where a facility may have stormwater compliance concerns.

A permittee should review its previous sampling results and consider whether problems have occurred repeatedly. Were elevated results associated with the same parameter? Did the results come from a particular discharge location or drainage area? Were corrective measures implemented? If so, did subsequent monitoring show improvement?

The IGP establishes Numeric Action Levels (“NALs”) for specified parameters. An NAL is not the same as a numeric effluent limitation, and an NAL exceedance does not, standing alone, establish a violation of an effluent limitation. NAL exceedances can, however, affect a facility’s status under the IGP’s Exceedance Response Action (“ERA”) requirements. Depending on the circumstances, the ERA process can require additional evaluation, changes to the SWPPP or BMPs, reporting, and involvement by a Qualified Industrial Stormwater Practitioner (“QISP”).

For that reason, previous monitoring results should not simply be filed away at the end of the reporting year. A recurring result may indicate that a facility should investigate a potential pollutant source or reconsider whether its existing BMPs are effective.

Is the Facility Prepared to Monitor?

The IGP contains specific requirements for stormwater monitoring, inspections, and visual observations. Facilities should review their monitoring procedures before a significant storm occurs rather than trying to determine what is required after rainfall has already begun.

This includes confirming monitoring locations and making sure the appropriate personnel and equipment are available. The SWPPP’s Monitoring Implementation Plan should also be reviewed to ensure that it remains consistent with the facility’s current operations and applicable monitoring requirements.

Visual observations are another part of the IGP’s monitoring program. Depending on the applicable requirements, observations may address conditions such as floating or suspended materials, oil and grease, discoloration, turbidity, odors, and trash or debris.

The facility should also confirm that personnel responsible for inspections, monitoring, and other stormwater-related activities understand their responsibilities and have completed any training required by the IGP.

Stormwater Compliance Does Not Stop with the Environmental Department

Employees throughout an industrial facility can affect stormwater compliance.

Personnel who handle materials, move equipment, manage waste, perform maintenance, or work in outdoor areas may encounter conditions that affect whether pollutants are exposed to stormwater. A facility’s written stormwater program therefore needs to be supported by its day-to-day operations.

Before storm season, facilities should make sure that appropriate employees understand how materials are supposed to be handled and stored, how spills or leaks should be addressed, and who should be notified when a condition could affect stormwater.

The question is not simply whether the facility has provided training. It is whether the people performing activities that could affect stormwater understand what the facility’s stormwater program requires of them.

What About the Facility’s Records?

The IGP also creates reporting and recordkeeping obligations. The State Water Resources Control Board’s Stormwater Multiple Application and Report Tracking System (“SMARTS”) is used for required submissions associated with the state’s stormwater general permits.

Before the rainy season, a permittee should review its SMARTS submissions and stormwater records to confirm that required information has been submitted and that the facility’s records are complete and accessible.

Those records may include inspection documentation, monitoring results, training records, SWPPP revisions, corrective-action documentation, and other materials relating to the facility’s stormwater program.

Recordkeeping can become particularly important when a facility encounters a compliance issue. If the Water Board later asks about a sampling result, discharge, or inspection, the facility may need to establish what occurred and how it responded. A clear record can help tell that story.

Why Preparing Before the Rain Matters

For an IGP permittee, preparing for the rainy season is not simply a matter of checking whether the facility looks ready for rain. It is an opportunity to evaluate whether the facility’s current operations, SWPPP, BMPs, monitoring program, and records remain consistent with the requirements that apply to the facility.

A facility should consider whether its operations have changed, whether its SWPPP still accurately describes the site, whether its BMPs remain effective, and what previous monitoring results may indicate. It should also confirm that the appropriate personnel understand their responsibilities and that the facility is prepared to conduct required monitoring when applicable storm events occur.

For facilities with a history of exceedances or other compliance concerns, the review can serve an additional purpose: identifying potential regulatory or enforcement issues before the next significant storm.

Stormwater compliance is an ongoing obligation under the IGP. Reviewing the program before the rainy season gives a facility an opportunity to address known issues while there is still time to do so—rather than waiting for the next stormwater sample, inspection, or regulatory inquiry to identify them.