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Requirements:
Procedures and Specific Requirements (5.2)

The following procedures are required. For a full list of implementing documents, see Exhibits (Forms & Tools).

General Permit

Sampling

Stormwater samples are required to be taken during two separate storm events between October 1 and May 31 of each year. The samples must be collected during the first hour of discharge and the storm event must be preceded by at least three dry working days. Samples are to be collected where the discharge leaves the property downstream of industrial activity areas. Samples are analyzed by an independent analytical lab for specific constituents required in the permit and for additional constituents that may be present because of industrial activities. Radioactivity is measured by the SLAC Radioanalysis Laboratory.

Inspections

Wet Weather

During the wet season (October 1 and May 31), monthly inspections must be conducted at each of the sampling locations. Inspection timing, in terms of storm events, is the same as for sample collection: during the first hour of discharge during a storm event that has been preceded by at least three dry working days.

Dry Weather

The general permit requires quarterly dry weather inspections of the drainages that are used to identify non-authorized discharges to the storm drain. If water is flowing in the drainage, upstream investigations to determine the source of water must be performed.

To document inspections, use Stormwater: Storm Drain Inspection Form [word] [pdf].

Permit Compliance Evaluation

The results of the annual compliance evaluation are reported to the RWQCB. If any results are out of compliance, SLAC is required to investigate the cause and bring the results into compliance. One set of criteria used to determine compliance is a list of parameter benchmark values listed in Stormwater: Discharge Parameter Benchmark Values Reference [pdf]. The primary tool for bringing the values back into compliance is evaluating and adjusting BMPs.

Best Management Practices

Stormwater BMPs are techniques, processes, activities, or structures meant to eliminate sources of pollutants that may enter the storm drain system. There are several guides to help determine if a set of BMPs applies to an area or process.

• For an assessment of whether BMPs apply to a situation, see Stormwater: Best Management Practices Determination Flow Chart [pdf].
• Area managers can use the Stormwater: General Inspection Checklist [word] [pdf] to identify potential impacts to the storm drain system to ensure all appropriate BMPs are in place.
• For a list of the BMP categories currently included in the SWPPP, see Stormwater: Best Management Practices Index [pdf].
• For a list of each industrial activity area at SLAC and applicable BMPs, see Stormwater: Industrial Activity Areas, Potential Pollutants, and Applicable BMPs [forthcoming].

Note: Taken together, these last two exhibits contain all the information that is required to determine which BMPs pertain to which SLAC industrial activity areas.

Contained Stormwater Disposal

Stormwater must be removed from containments regularly and disposed of properly. Options include

• Adding it to cooling tower water
• Discharging it directly to the sanitary sewer system if it meets industrial wastewater permit requirements
• If characterized stormwater meets water quality objectives, it may be discharged to the storm drain system

All discharges of contained water to the storm drain system must be documented using Stormwater: Contained Water Release Form [word] [pdf]. Copies of this form must be sent the stormwater program manager.

Additional Permits

Determination

To determine if an additional permit may be required, see Stormwater: Permit Requirement Determination Flow Chart [pdf]. If a permit may be required, the stormwater program manager should be contacted as early in the process as possible.

Note: ES&H or a qualified consulting firm can prepare JARPA permit applications.

Construction Projects

Planning for Low-impact Development

Construction projects should incorporate low-impact development (LID) design criteria whenever possible (see United Facilities Criteria, Low Impact Development [pdf]). The goal of LID site design is to reduce the hydrologic impact of development to creeks and streams by maintaining pre-development drainage patterns. The optimal LID site design minimizes runoff volume and preserves existing flow paths.

Construction Project Requirements

Any type of construction, including building repair, remodeling or excavating and grading projects, must include mitigating measures to minimize impacts to stormwater and the stormwater drainage system. Potential impacts from construction projects include spills, sediment, debris, and chemicals or other materials entering the storm drain system.

In planning a project, review the type of materials that will be used and removed, equipment and material staging needs, and storm drain protection and sediment management practices that may be required. For a list of steps that must be taken throughout the project to protect the stormwater drainage system, see Stormwater: Construction Site Requirements [pdf]. See also Stormwater: Category 13 BMPS - Building Repair, Remodeling, and Construction [pdf] for recommended mitigation measures.

Storm Drain System Maintenance and Upgrades

Inspections

The storm drain system must be inspected periodically to identify potential problems before they become major repairs. Items to check include storm drain catch basins, pipes and channels, sediment traps and weirs.

Maintenance

Maintenance work in lined channels or culverts that does not impact riparian or wetland vegetation does not require a permit. To minimize the risk of flooding or flow constriction

• Remove debris, excessive sediment build-up, and opportunistic plants from channels and culverts as needed
• Prevent erosion of the channel banks by repairing the bank in a timely manner

Note: If maintenance is not performed frequently, it may become reclassified as repair work and require a JARPA permit before proceeding.

Enhancements

The storm drain system can be enhanced with structural BMPs such as inserts, wattles, sediment traps, and bioswales. When structural BMPs are used, scheduled preventive maintenance and inspections should be included to ensure they are operating as designed and continue to be effective in minimizing pollutants.

continue to Training (5.3)