Corporate Responsibility and Sustainability Report 2022

Our Approach

Water is essential to operating our infrastructure—including our vast network of hydroelectric generating stations—just as it is essential to our customers in their daily lives. PG&E is promoting sustainable water use in a number of ways:

• Strategically managing our power generation facilities,
• Reducing water consumption at PG&E offices and service centers, and
• Providing outreach and guidance to customers on how to reduce water usage.

PG&E also reports our water data and strategies to the CDP (PDF).

Power Generation

At our Diablo Canyon Power Plant, we use saltwater from the Pacific Ocean for once-through cooling, with a maximum discharge of 2.5 billion gallons per day, set by the facility’s Clean Water Act permit. PG&E closely monitors the marine environment at the plant by conducting regular studies and sampling, also required under the plant’s Clean Water Act permit.

PG&E relies on air for cooling at our three natural gas power plants: Humboldt Bay Generating Station, Gateway Generating Station, and Colusa Generating Station.

Additionally, PG&E owns and operates one of the nation’s largest investor-owned hydroelectric systems. Our hydroelectric power plants are largely non-consumptive, meaning that after water passes through turbines to produce electricity, it is returned to the river. In addition, PG&E’s 1,212 MW Helms Pumped Storage Project uses water for energy storage to help balance daily variations in electric demand.

Water Conservation

PG&E’s offices and service centers rely on water for restrooms, kitchens, mechanical system cooling, vehicle washing, and landscape irrigation. We remain focused on identifying, reporting, and repairing leaks quickly; managing our irrigation systems; installing low-flow plumbing fixtures; and replacing landscaping with drought-resistant approaches.

PG&E also offers customers a range of options to help them reduce their water use, such as direct installation of low-flow shower heads and faucet aerators. We also deliver free wood mulch to homes and businesses to help them reduce water needed for plants and trees.

2021 Milestones

• Helped customers save water. Altogether, customers who participated in PG&E’s programs reduced water usage by over 92 million gallons in 2021, based on our most common energy-efficiency measures that deliver water savings.
• Hosted the 18th-annual Water Conservation Showcase, which covered climate positive landscape design, watershed stewardship, and other topics with a range of institutions such as the UC Davis Center for Water-Energy Efficiency, Marin Municipal Water District, and the California Academy of Sciences.
• Repurposed nearly 1 million gallons of water used in hydrostatic testing for beneficial reuse, including toward irrigation, dust suppression, backfill compaction, and project restoration—reseeding and watering all disturbed areas to return them to their pre-project state.
• Reduced water use at our facilities by installing 15 flow monitoring units at seven different facilities, to provide real time readings and alert facility managers about unusual water usage. Detected leaks can be immediately repaired and other high usage can be investigated to encourage conservation. As a result of this and other sustainability efforts, water usage dropped by 10% relative to 2020.

Measuring Progress

• 1. Net operating capacity on December 31, 2021: Diablo Canyon: 2,240 MW; Humboldt Bay Generating Station: 163 MW; Gateway Generating Station: 580 MW; Colusa Generating Station: 657 MW.^{1a, 1b, 1c, 1d}
• 2. The California Water Board adopted a policy in 2010 that generally requires power plants with once-through cooling to install cooling towers or other significant measures to reduce marine impacts by at least 85%. Diablo Canyon must comply with this policy by November 2024 for Unit 1 and August 2025 for Unit 2. In January 2018, the CPUC approved a joint proposal to retire Diablo Canyon at the end of its current Nuclear Regulatory Commission licenses, November 2024 and August 2025. Until plant retirement, Diablo Canyon will pay an annual interim mitigation fee as required by the California Water Board policy.²
• 3. Freshwater sources consist of well water for backup and emergency purposes.³
• 4. PG&E monitors water usage at permitted public water systems owned and operated by PG&E. These systems are metered in accordance with state regulations. Approximately three-fourths of water withdrawal by permitted systems in 2021 was comprised of remediation and process water used at the Hinkley Compressor Station.⁴
• 5. These figures include once-through cooling discharge (equivalent to withdrawal amounts) plus estimated reverse osmosis system brine/backwash discharge.⁵
• 6. Colusa Generating Station uses a zero-liquid discharge system. A septic system is used to manage sanitary waste.⁶
• 7. In 2021, more than three-fourths of the water used in hydrostatic testing was recycled or reused for irrigation, dust control, or project restoration.⁷