Addendum No. 2 to the Facilities Master Plan Program EIR for the RP-5 Expansion Offsite Facilities Projects

IEUA, as the Lead Agency for the IEUA RP-1 Project, prepared and certified the Final Program Environmental Impact Report (Final Program EIR) for the IEUA Facilities Master Plans pursuant to the California Environmental Quality Act (CEQA) on March 15, 2017. The Final Program EIR evaluated a long-term program of infrastructure improvements intended to support IEUA’s wastewater treatment, recycled water, groundwater recharge, and utility operations. The analysis in the Final Program EIR assessed a broad range of reasonably foreseeable future projects across multiple IEUA facilities at a programmatic level and organized those projects into three categories: treatment facility upgrades, recycled water and groundwater recharge facilities, and auxiliary systems and support facilities. The Final Program EIR evaluated a range of reasonably foreseeable future upgrade projects related to the modernization, rehabilitation, and improvements of the RP-1 facility, including: 1) solids treatment and capacity upgrades, such as solids treatment rehabilitation, sludge thickening upgrades, and capacity rehabilitation; 2) digestion system improvements, including digester gas mixing, digester mixing upgrades, and digester cleaning and rehabilitation; 3) digester gas handling and treatment improvements, including flare improvements, flare system improvements, and digester gas mixing, which ensure that gas produced at RP-1 is beneficially used; 4) thermal support systems for digestion, including expansion, rehabilitation, and optimization of digestion and solids treatment systems, with upgrades to solids processing, digester operation, and supporting thermal infrastructure; 5) emergency power generation and electrical system upgrades, including enhancements to support reliable plant operations and installation, or improvement of emergency power infrastructure to maintain operations during outages or peak demand; 6) odor control improvements, including projects identified as odor control improvements and odor control improvements evaluation, which include foul air treatment systems, clarifier covers, and odor control equipment; 7) chemical handling and disinfection system improvements identified as disinfection pump improvements and liquid treatment rehabilitation projects that encompass the upgrade and expansion of RP-1 liquid treatment and disinfection systems, such as increased liquid treatment capacity to meet projected flows, modernization of disinfection pumping and dosing infrastructure, and optimization of post-filtration chlorination; and 8) other improvements, including headworks rehabilitation, clarifier rehabilitation, mixed liquor return pump improvements, electrical and heating, ventilation and air conditioning (HVAC) system upgrades, and recycled water facilities. The IEUA RP-1 Project implements a portion of the long-term modernization, rehabilitation, and capacity improvements previously analyzed for the RP-1 facility in the Final Program EIR. The project applicant seeks the following modifications to the existing Solids Thickening Facility pursuant to South Coast AQMD Application Number (A/N) 648840: 1) replacement of the existing sludge gravity thickeners, the sludge blending tank, and the dissolved air flotation thickener and its associated recirculation pump with eight new rotary screen thickeners and two solids blending tanks, which will be installed within a new building; and 2) construction of three new acid phase digesters and one sulfur removal treatment system with four iron sponge units to treat the gas produced from the acid phase digesters. The project applicant also seeks to install: 1) a new emergency diesel-fueled internal combustion engine (South Coast AQMD A/N 648201), rated at 2,206 brake horsepower, to provide supplemental backup power to the four existing emergency engines and ensure uninterrupted operation of the wastewater treatment process during electrical outages; 2) a new digester gas/natural gas-fired boiler (South Coast AQMD A/N 648202), with a rated capacity of 13.902 million British thermal units per hour, to provide additional heating capacity to the existing hot water loop system serving the seven existing anaerobic digesters and the three new acid phase digesters; and 3) a new odor control system (South Coast AQMD A/N 648203), with an operating capacity of 14,370 standard cubic feet per minute, comprised of one pre-treatment aqueous scrubber to remove ammonia from foul air and one biofilter to treat foul air from the sludge thickening building, rotary screen thickeners, sludge blending tanks, centrifuge sludge dewatering building, sludge silos, and drainage pump station. Lastly, the IEUA RP-1 Project includes replacement of three existing 10,300-gallon sodium hypochlorite storage tanks with four new 12,189-gallon sodium hypochlorite storage tanks; however, these modifications do not require a permit pursuant to South Coast AQMD Rule 219(d)(13)(U).