Section 404 Permit Determinations and Construction Stormwater Pollution Prevention Plan, Redhawk Makeup Pipeline, Palo Verde Nuclear Generating Station

In 2001, ACS completed three different projects related to the construction and operation of the Redhawk Makeup Pipeline. The Redhawk Makeup Pipeline carries treated effluent from the Palo Verde Nuclear Generating Station (PVNGS) Reservoir to the Redhawk Combined Cycle Power Plant Makeup Water Surge Pond approximately 4.5 miles to the south. Initially, ACS completed a Clean Water Act (CWA) Section 404 determination for the pipeline route. Based on a jurisdictional delineation (JD) of the East Wash and a review of Section 404 regulations, ACS determined that Nationwide Permit (NWP) 12 covered the construction and operation of the pipeline and that an individual permit from the U.S. Army Corps of Engineers (the Corps) was not required. ACS also determined that CWA Section 401 Certification had been pre-certified for NWP 12 by the Arizona Department of Environmental Quality (ADEQ). ACS also provided PVNGS with 404-related information to include in the pipeline’s operations and maintenance plan. Also prior to construction, ACS worked with PVNGS engineering and environmental personnel to write contract specifications for the Storm Water Pollution Prevention Plan (SWPPP) required for pipeline construction. ACS also reviewed the construction company’s SWPPP for regulatory accuracy, workability, and adherence to PVNGS site environmental requirements. Shortly after the pipeline was completed, an Arizona Summer Monsoon event caused high flow conditions in the East Wash that resulted in significant scour around the pipeline. Although the pipeline was not damaged by the flow event, PVNGS engineers determined that protection for the pipeline was necessary in the event of additional high flow events in the East Wash. Based on information obtained by ACS as part of the Section 404 determination for pipeline construction, ACS determined that Nationwide Permit (NWP) 43 covered the construction of the stormwater management facility that PVNGS intended to construct to protect the pipeline. ACS also determined that CWA Section 401 Certification had been pre-certified for NWP 43 by ADEQ. ACS completed the work for the Redhawk Makeup Pipeline simultaneously with out work on the Aquifer Protection Permit (APP) for the Redhawk Combined Cycle Power Plant.