CPSWQ cheat sheet

Construction General Permit coverage is generally required for disturbances of one acre or more, or less than one acre if part of a larger common plan of development or sale that totals one acre or more.

A Stormwater Pollution Prevention Plan (SWPPP) must identify pollutant sources, describe BMPs, include a site map, and specify inspection, maintenance, and recordkeeping procedures before construction begins.

The construction site operator must install and maintain erosion and sediment controls, stabilize disturbed areas, manage all construction wastes, and control discharges from dewatering and washout activities.

A site inspection must occur at least once every seven calendar days, or once every 14 calendar days and within 24 hours of the end of any storm event that produces 0.25 inches of rain or more.

Disturbed portions of the site must be stabilized as soon as practicable, but no later than 14 days after construction activity has permanently ceased on that portion of the site.

A discharge of stormwater from a construction site must not cause or contribute to an exceedance of an applicable water quality standard; the SWPPP must be modified when site conditions or BMP effectiveness change.

Non-stormwater discharges such as concrete washout, vehicle washing, and equipment rinsing must be eliminated or covered by a separate permit; washout water is never allowed to enter the storm drain system.

The SWPPP and inspection records must be retained for at least three years after the permit is terminated or the Notice of Termination is submitted, and must be available for review by the permitting authority.

MS4 permits are issued under the NPDES program; Phase I covers municipalities serving populations of 100,000 or more, and Phase II covers regulated small MS4s in urbanized areas or as designated by the permitting authority.

Six minimum control measures apply to small MS4 programs: public education and outreach, public participation, illicit discharge detection and elimination, construction site runoff control, post-construction runoff control, and pollution prevention/good housekeeping.

An illicit discharge detection and elimination program requires a storm sewer map, an ordinance or regulatory mechanism prohibiting illicit discharges, and procedures for tracing and removing them.

Post-construction stormwater management must address new development and redevelopment using structural and non-structural BMPs, often with numeric criteria such as retaining the pre-development hydrology or treating the first flush volume.

Total Maximum Daily Load (TMDL) wasteload allocations assigned to an MS4 must be implemented through specific BMPs and measurable milestones documented in the permit or a stormwater management plan.

Municipal good housekeeping includes employee training, controls for municipal vehicle and equipment maintenance, and management of municipal operations such as street sweeping and catch basin cleaning.

Annual reporting to the permitting authority typically covers BMP implementation status, measurable goals, monitoring results, and progress toward permit compliance deadlines.

Stormwater management programs must include measurable goals and an evaluation and assessment process to determine whether the program is reducing pollutants to the maximum extent practicable (MEP).

Industrial facilities in regulated sectors (identified by SIC codes in the permit) that discharge stormwater associated with industrial activity require NPDES permit coverage, typically through a general industrial stormwater permit.

A Stormwater Pollution Prevention Plan (SWPPP) for an industrial facility must include a facility description, a site map, an inventory of exposed materials, a list of significant spills, and a description of controls and monitoring.

The SWPPP must be signed and certified by a responsible corporate officer or duly authorized representative and retained on site or at a readily accessible location.

Facilities must implement Best Available Technology Economically Achievable (BAT) and Best Conventional Pollutant Control Technology (BCT), and where applicable, meet numeric effluent limits from TMDLs or state standards.

Quarterly visual inspections and annual comprehensive site evaluations are commonly required; the annual evaluation must be documented and used to revise the SWPPP as needed.

Benchmark or numeric monitoring values trigger corrective actions when exceeded; the facility must investigate the cause, implement additional BMPs, and document the corrective action in the SWPPP.

Eliminating non-stormwater discharges is a core requirement; authorized non-stormwater discharges must be identified in the SWPPP and, where required, covered by a separate NPDES permit.

A Notice of Intent (NOI) is typically submitted to obtain permit coverage, and a Notice of Termination (NOT) is submitted when industrial activity ceases or the facility no longer discharges stormwater.