Irvine – California – Water Quality Report 2025: PFAS Testing, Infrastructure Concerns & Safety across your city
Irvine Ranch Water District (IRWD) provides comprehensive water and sewer services to over 300,000 residents across 180 square miles in central Orange County, including the city of Irvine and portions of Costa Mesa, Lake Forest, Newport Beach, Orange, and Tustin. Established in 1961 as an independent California special district, IRWD operates with more than 101,000 connections and delivers high-quality drinking water through an advanced distribution system.
IRWD sources its drinking water from two primary sources: approximately 65% comes from local groundwater wells in the Orange County Groundwater Basin ranging from 400 to 2,000 feet deep, while the remaining 35% is imported water purchased from the Metropolitan Water District of Southern California. This imported water originates from the Colorado River via the Colorado River Aqueduct and from Northern California via the State Water Project. IRWD’s diversified water supply ensures reliability during droughts and emergencies while maintaining some of the lowest water rates in Orange County. The district has earned J.D. Power’s top customer satisfaction award for four consecutive years, ranking as the best midsize water utility in the Western United States.

Irvine Water Quality: Current Status (2024-2025)
Latest Testing Results
- Lead and Copper Monitoring: IRWD completed its EPA-required lead service line inventory in September 2024, confirming no lead or galvanized requiring replacement service lines exist in the distribution system. The district maintains full compliance with EPA lead and copper regulations.
- Testing Scope: IRWD conducts over 250,000 water quality tests annually using its state-certified laboratory, sampling from more than 100 routine points throughout the system to ensure comprehensive monitoring.
- Compliance Status: IRWD’s water meets or exceeds all federal and state drinking water standards, maintaining full compliance with EPA and California Department of Public Health regulations, which are among the most stringent in the nation.
Water Sources
- Local Groundwater Wells: Primary source (approximately 65% of supply) from high-quality wells in the Orange County Groundwater Basin, Irvine sub-basin, and Lake Forest sub-basin, managed by the Orange County Water District.
- Imported Water: Secondary source (35% of supply) purchased from Metropolitan Water District, originating from the Colorado River and Northern California via the State Water Project aqueduct system.
- Source Water Protection: Comprehensive monitoring programs including the Orange County Water District’s management of groundwater quality and ongoing collaboration with regional partners for watershed protection.
Advanced Treatment Technology
- Metropolitan Treatment: Imported water is treated at MWD’s Diemer Filtration Plant in Yorba Linda using advanced multi-barrier treatment including chloramines (chlorine and ammonia combination) for effective disinfection.
- Groundwater Quality: Local wells produce naturally high-quality water that requires minimal treatment, though IRWD has installed treatment systems when needed to address specific contaminants like PFAS.
- PFAS Protection: IRWD has proactively addressed PFAS concerns by shutting down affected wells or installing treatment systems, ensuring no detectable PFAS in delivered water – meeting EPA standards five years ahead of the 2029 deadline.
Infrastructure Modernization
- State-Certified Laboratory: IRWD operates one of the best-equipped water quality laboratories in Southern California, featuring cutting-edge testing equipment and certified staff for comprehensive water analysis.
- Recycled Water Innovation: Pioneering water recycling initiative providing approximately 21% of total supply for irrigation and industrial uses, featuring the distinctive “Irvine Purple” pipes that originated at IRWD and are now recognized worldwide.
- Smart Water Management: Advanced monitoring systems throughout the distribution network combined with allocation-based conservation rate structure that rewards efficient water use and maintains some of the lowest rates in Orange County.
Customer Protection Initiatives
IRWD provides exceptional customer service through 24/7 emergency assistance at 949-453-5300, comprehensive water quality testing, and transparent annual reporting. The district offers free water conservation devices, home and business water audits, landscape workshops, and educational tours. IRWD’s allocation-based rate structure provides customers with reasonable water budgets based on household size and landscape area, with lower costs for efficient use. The district’s commitment to innovation, environmental stewardship, and customer satisfaction has earned recognition as the top-rated water utility in the Western United States for customer satisfaction four years running, demonstrating its dedication to providing safe, reliable drinking water while preparing for future challenges including climate variability and emerging contaminants.
Recommendations for Irvine Residents

Monitor Your Water Quality
Contact IRWD Customer Service at 949-453-5300 for any water quality concerns including taste, odor, or appearance issues. Request the annual Water Quality Report at info@IRWD.com or visit IRWD.com/water-quality for detailed testing results.

Use Water Efficiently
Take advantage of IRWD’s free water conservation devices, home water audits, and landscape workshops. Stay within your monthly water allocation to benefit from IRWD’s budget-based rate structure that rewards efficient use.

Consider Home Filtration
While IRWD’s water meets all safety standards, homes may benefit from NSF-certified filters to address taste preferences, water hardness (varies by location and season), or for additional peace of mind regarding trace contaminants.

Explore Recycled Water
Consider IRWD’s award-winning recycled water program for landscape irrigation, which helps conserve potable water and reduce costs. Contact IRWD to learn about availability in your area and dual-plumbing opportunities.

24/7 Customer Support
Contact IRWD Customer Service at 949-453-5300 for 24-hour emergency assistance, billing questions, service start/stop, or water quality concerns. Visit IRWD.com for online account management and educational resources.
Frequently Asked Questions
Is Irvine’s tap water safe to drink?
Yes, IRWD’s tap water is safe and meets or exceeds all federal and state drinking water standards. California’s drinking water standards are among the most stringent in the nation and often supersede federal requirements.
IRWD maintains a state-certified laboratory that performs over 250,000 tests annually on water from more than 100 sampling points. The district’s water sources include high-quality local groundwater and treated imported water, both subject to rigorous monitoring. IRWD publishes annual Water Quality Reports detailing all testing results and maintains full transparency about water safety and quality.
Why does water hardness vary in my area?
Water hardness varies depending on your location within IRWD’s service area and the time of year due to the blend of water sources used:
1. Local groundwater: Moderately hard, typically lower in mineral content
2. Colorado River water: Hard, with higher mineral content
3. Northern California water: Also typically hard
IRWD blends these sources throughout the year based on supply needs and system demands. While hardness doesn’t affect safety, it can cause white spots on dishes and may prompt some residents to consider water softening systems. Check your current Water Quality Report for specific hardness levels by source.
Does IRWD’s water contain PFAS?
No, IRWD’s delivered water contains no detectable PFAS (per- and polyfluoroalkyl substances). The district has been proactive in addressing PFAS concerns:
• Early action: When PFAS was discovered in some Orange County wells in 2018 and 2020, IRWD either shut down affected wells or installed effective treatment systems
• Ahead of schedule: IRWD already meets EPA’s new PFAS standards that don’t take effect until 2029
• Ongoing monitoring: Continuous testing ensures no PFAS reaches customers
• Regional collaboration: Working with Orange County Water District and other utilities to understand and address PFAS in the groundwater basin
IRWD customers can be confident that their drinking water is PFAS-free through the district’s proactive protection measures.
How does IRWD’s allocation-based billing work?
IRWD uses a budget-based water rate structure that rewards efficient water use:
Your Water Budget:
• Each customer receives a monthly water allocation based on household size, landscaped area, and weather conditions
• The allocation provides reasonable water for your needs while encouraging conservation
Rate Tiers:
• Within budget (0-100%): Lower rate for efficient use
• Over budget (101%+): Higher rates as IRWD must purchase expensive imported water
This system keeps rates low for efficient users while covering the higher costs of excess water demand. Contact IRWD for a personalized rate estimate or to understand your specific allocation.
Contaminants of Concern

Disinfection Byproducts
Source: Formed when disinfectants such as chloramines (used in imported water treatment) react with naturally occurring organic matter in source water; levels may be more prevalent during warmer months
Health Effects: Long-term exposure to elevated levels may increase risk of certain cancers and potentially affect liver, kidney, and central nervous system
Current Levels: Monitored quarterly throughout the distribution system with levels maintained below EPA maximum contaminant levels EPA Limits: 80 ppb for total trihalomethanes (TTHMs) and 60 ppb for haloacetic acids (HAA5)

1,4-Dioxane
Source: Industrial solvent that can contaminate groundwater through manufacturing wastewater, plastic production runoff, and landfill leachate, detected at low levels in some Orange County groundwater
Health Effects: Classified by EPA as a likely human carcinogen, with potential concerns for liver and kidney effects from long-term exposure to elevated levels
Current Status: Detected at low levels in some IRWD water sources, well below health advisory levels. IRWD monitors regularly and coordinates with Orange County Water District on regional groundwater management EPA Advisory: No federal maximum contaminant level established; California monitoring ongoing
Please read – our information
The information presented on cleanairandwater.net is compiled from official water quality reports, trusted news sources, government websites, and public health resources. While we strive for accuracy and thoroughness in our presentations, we are not scientists, engineers, or qualified water quality professionals.
Our mission is to present water quality information in an accessible, real-world format that helps people understand what’s in their water and make informed decisions about their health and safety. We believe that complex environmental information should be available to everyone in a format that’s easy to understand.
We make every effort to ensure our content is current and accurate, but we cannot guarantee that all information is complete or error-free. This website should not replace official communications from your local water utility or health department. We always recommend consulting official sources for the most up-to-date information regarding your specific water system.
Clean Air and Water is not liable for any unintentional errors, omissions, or outdated information. The content on this site is provided for informational purposes only and should not be considered professional advice.
