3. Manage Site Your Construction Site for Clean Stormwater
Keep a current SWPPP on-site whenever construction or support activities are active. The SWPPP should identify the stormwater team, construction schedule, summary of potential pollutants, control measures to prevent discharges, records of inspections, maintenance actions, and corrective actions.
Stormwater management is an adaptive process and the SWPPP is a living document. Revise the SWPPP and site map as necessary during the permit coverage to reflect current conditions. Update the SWPPP within 7 days whenever there is a change in design, construction, operation, or maintenance at your site; or a change to the stormwater team.
Perform routine inspections to ensure the SWPPP is implemented correctly and effectively. Additional inspections prior to storm events are advantageous to managing stormwater runoff and associated pollutants. Conduct inspections using the ADEQ CGP Inspection form, or alternative form that documents all the information required by the CGP. During the inspection, follow these recommendations:
- Ensure structural control measures are installed according to SWPPP specs and function as intended
- Assess the effectiveness of good housekeeping practices and pollution prevention procedures
- Observe conditions across the site for evidence of erosion or discharge of pollutants
If a deficiency is observed during the inspection, evaluate the cause of the problem and potential solutions. Implement corrective measures within seven days and update the SWPPP as necessary to reflect current conditions.
The AASHTO Maintenance Stormwater Field Guide provides a quick reference for inspection, control measure maintenance and common operational practices.
5. Terminate the CGP Coverage with an NOT
To terminate CGP coverage, submit a Notice of Termination (NOT) using myDEQ. Before terminating CGP coverage, at least one of these six conditions must be met:
- Site has final stabilization (See CGP, Part 3.4.2 for details).
- All soil-disturbing activities are complete. All trash and temporary control measures are removed. And either:
- Uniform vegetation covers all unpaved areas with a density of 70% of the pre-construction native background
- Equivalent permanent stabilization measures (such as riprap, gabions, gravel, or geotextiles) have been employed.
- For individual lots in residential construction:
- Final stabilization is completed, as described immediately above; or
- Temporary stabilization has been completed, including perimeter controls, on a lot and the homeowner has been informed of the need for the final stabilization.
- For agricultural land, the disturbed areas have been returned to pre-construction agricultural use.
- Another operator has assumed control of unstabilized areas with another AZPDES permit.
- Temporary stabilization at a residence is complete and transferred to owner or an HOA.
- Planned construction activities were never started.
- Operator has obtained coverage under another AZPDES permit.
- Operator qualifies for Alternative Stabilization (See CGP Part 3.4.3 for details)
- Sites with additional retention capacity must meet the following conditions*:
- There are no outfalls that discharge to a perennial or intermittent water body;
- All stormwater generated by disturbed areas of the site is directed to retention basins;
- The operator complies with good housekeeping measures;
- The operator maintains the capacity of the retention basins; and
- The operator determines temporary and final stabilization requirements for the site to reduce or minimize the discharge of sediment and other pollutants, per 3.4.1 and 3.4.2.
- Site is returned to pre-construction discharge conditions. The stormwater discharge from the site's pre- and post-construction activities is equal or less than in volume and pollutant load from disturbed areas, as calculated by a professional.
- Arid, semi-arid, and drought-stricken areas
The area is seeded or planted that provides at least 70% native vegetation cover of local undistributed areas within 3 years and, to the extent necessary to prevent erosion on the seeded or planted area, non-vegetative erosion controls have been applied that provide cover for at least 3 years without active maintenance.
* This section does not apply to sites with retention capacity that meets or exceeds the 100 year/ 2-hour storm event, as calculated by an Arizona registered professional engineer, geologist or landscape architect or equivalent.