Riverside County Water Quality Data 2025: What Consumer Confidence Reports Show by Utility

Riverside County draws its drinking water from five major utilities serving more than 2.4 million residents across communities that range from Jurupa Valley in the northwest to Temecula in the south and Lake Elsinore in the west. Consumer Confidence Reports published by Rancho California Water District, Riverside Public Utilities, Elsinore Valley Municipal Water District, Eastern Municipal Water District, and Jurupa Community Services District for 2024 show significant variation in water quality across the county. Hardness in the Temecula and Murrieta service area averaged 173 mg/L (10.1 grains per gallon) in 2024 per RCWD's published report. Total dissolved solids range from approximately 350 parts per million in Jurupa Valley to 1,010 parts per million in the Lake Elsinore area. Contaminants detected across these systems include trihalomethanes, hexavalent chromium, arsenic, and nitrates, all below federal legal limits but in some cases above California's more stringent health-based advisory levels. Every utility in the county met state and federal compliance standards in 2024.

Schedule a free water test in Riverside County to see exactly what is in your tap water. Call us at (949) 873-1129.

Where does Riverside County drinking water come from?

Riverside County is one of the most geographically diverse counties in California, stretching from the western edge of the Inland Empire to the Arizona border. The portion where most residents live, covering cities like Riverside, Corona, Temecula, Murrieta, Lake Elsinore, Moreno Valley, Hemet, and Jurupa Valley, is served by utilities that blend two primary water sources.

The first source is Colorado River water imported by the Metropolitan Water District of Southern California (MWD) through the Colorado River Aqueduct. MWD treats this water at the Diemer and Skinner filtration plants before delivering it to local utilities. Colorado River water enters the county already carrying dissolved calcium, magnesium, and sodium accumulated across its course through the desert Southwest.

The second source is local groundwater pumped from alluvial basins including the Riverside Basin, the San Jacinto Basin, and the Elsinore Basin. Groundwater picks up additional minerals as it percolates through the region's geology, which includes carbonate rock formations rich in calcium and magnesium. Utilities that draw more heavily from local wells typically deliver harder water with higher TDS than those relying primarily on MWD imports.

The blend ratio shifts seasonally based on snowpack, reservoir conditions, and drought status. Dry years push utilities toward heavier groundwater reliance, which can raise hardness and TDS noticeably at the tap. For a broader look at how this dynamic plays out across the Inland Empire, see our analysis of water hardness by city across the Inland Empire.

How was this water quality data compiled?

All utility-level data in this article comes from each utility's Consumer Confidence Report (CCR), also called a Water Quality Report or Annual Water Quality Statement. The federal Safe Drinking Water Act requires every public water system serving 25 or more people to publish a CCR annually by July 1, covering water quality data for the prior calendar year.

California utilities must file these reports with the State Water Resources Control Board's Electronic Annual Reporting database. The reports are public records, searchable by water system name at waterboards.ca.gov.

Data in the table below reflects 2024 CCRs unless otherwise noted. Where utilities reported total dissolved solids rather than hardness in mg/L, TDS is presented. TDS and hardness are related but not identical measurements; TDS captures all dissolved minerals, while hardness specifically tracks calcium and magnesium. A water test at your tap provides more precise data than any utility-wide average.

What do Riverside County water quality reports show by utility?

The table below summarizes key water quality indicators from 2024 Consumer Confidence Reports across the five major Riverside County utilities.

Sources: RCWD 2024 Consumer Confidence Report (ranchowater.com); RPU 2024 Water Quality Report (riversideca.gov); EVMWD Consumer Confidence Report (evmwd.com); EMWD 2024 Annual Report (emwd.org); JCSD water quality data. All utilities reported compliance with state and federal standards.

What does Rancho California Water District's 2024 water quality report show?

Rancho California Water District serves approximately 85,000 connections across Temecula, Murrieta, and parts of the Southwest Riverside County wine country. RCWD draws from a combination of MWD-delivered Colorado River water, local groundwater, and State Water Project supplies.

RCWD's 2024 Consumer Confidence Report states that water hardness averaged 173 milligrams per liter, equal to 10.1 grains per gallon. The Water Quality Association classifies water above 10.5 gpg as very hard, placing RCWD's average supply just at the border between hard and very hard. Hardness at individual taps may vary from the district average based on local groundwater blend ratios in different pressure zones.

Trihalomethanes (TTHMs) were detected in RCWD's distribution system, as in virtually all chlorinated water systems. TTHMs are disinfection byproducts that form when chlorine reacts with organic matter in source water. RCWD's detected levels fell below the federal Maximum Contaminant Level of 80 micrograms per liter.

For Temecula residents who want to know exactly what their tap delivers, a free water test in Temecula provides a direct reading rather than a district average. Murrieta residents can schedule a free water test in Murrieta for the same reason.

If the hardness reading at your Temecula or Murrieta tap comes back above 10 gpg, a water softener (Temecula or Murrieta) addresses scale buildup and the day-to-day signs of hard water covered in our guide to hard water signs.

What does Riverside Public Utilities' water data show for the City of Riverside?

Riverside Public Utilities serves the City of Riverside and draws from Lake Matthews, the Metropolitan Water District's Inland Feeder system, and local groundwater wells. The blend ratio varies by season.

The 2024 Water Quality Report from RPU shows total dissolved solids at approximately 588 parts per million, which is meaningfully higher than the EPA's non-enforceable secondary standard of 500 ppm. Historical Consumer Confidence Reports show total hardness ranging from approximately 170 to 255 mg/L (10 to 15 grains per gallon) depending on season and groundwater blend.

Detected contaminants in RPU's system include total trihalomethanes (including bromodichloromethane, bromoform, chloroform, and dibromochloromethane), dichloroacetic acid, and hexavalent chromium. All were below federal Maximum Contaminant Levels. Chromium-6 in particular has been a focus of California regulators; the state set a Maximum Contaminant Level of 10 micrograms per liter in 2023, the first such standard in the nation.

Our dedicated Riverside water treatment guide covers source water, local geology, and treatment options in more detail. Riverside residents can schedule a free water test in Riverside to confirm which contaminants are present at their specific address.

For those whose tap results show high TDS or chromium-6 concern, reverse osmosis systems in Riverside reduce both, along with TTHMs, at the drinking tap. A whole house water filtration system in Riverside addresses contaminants at every fixture.

What does EVMWD's water quality report show for Lake Elsinore and surrounding communities?

Elsinore Valley Municipal Water District serves approximately 180,000 residents across Lake Elsinore, Wildomar, Canyon Lake, and portions of Menifee. EVMWD draws from a combination of imported MWD water and local groundwater from the Elsinore Basin.

The Elsinore Basin sits in a structural trough between the Santa Ana and Elsinore mountains. Groundwater in this basin contacts carbonate and sulfate minerals over long percolation paths, picking up a significant mineral load. EVMWD's Consumer Confidence Reports show total dissolved solids at approximately 1,010 parts per million, more than double the national average of around 500 ppm and above the EPA's 500 ppm secondary standard.

EVMWD's 2024 CCR identified 10 contaminants detected above health advocacy guidelines, though all remained below enforceable legal limits. Those contaminants include arsenic, hexavalent chromium, trihalomethanes (including bromodichloromethane, bromoform, chloroform, and dibromochloromethane), chlorate, nitrate, and nitrite.

Arsenic is a naturally occurring contaminant in groundwater across Southern California. The federal MCL is 10 parts per billion. California is working toward a more protective standard. For residents concerned about arsenic or TDS at this level, a point-of-use reverse osmosis system certified to NSF/ANSI Standard 58 reduces arsenic by 90 to 99 percent alongside TDS.

What does Eastern Municipal Water District report for Moreno Valley, Hemet, and Perris?

Eastern Municipal Water District is one of the largest utilities in Riverside County, serving approximately 513,000 residents across Moreno Valley, Perris, Hemet, San Jacinto, and portions of Temecula. EMWD purchases the majority of its drinking water supply from the Metropolitan Water District, making its water source primarily treated surface water from the Colorado River and State Water Project.

EMWD's 2024 water quality program conducted more than 48,000 individual tests across 36 supply sources, testing 8,100 samples for 382 different contaminants. EMWD reported meeting all state and federal drinking water standards in 2024, a compliance record consistent with its history.

Because EMWD relies heavily on MWD-treated surface water rather than local groundwater, its water tends to carry lower mineral loads than utilities drawing primarily from alluvial basins. Contaminants detected in EMWD's distribution system include arsenic, chloroform, and hexavalent chromium, consistent with Southern California utilities drawing from Colorado River-sourced surface water that travels long distances through aging distribution infrastructure.

EMWD's service area spans multiple sub-regions with different groundwater influence levels. Hemet and San Jacinto, which have a longer history of local well use, may see different hardness profiles than Moreno Valley zones served primarily through MWD connections.

What does Jurupa Community Services District water data show?

Jurupa Community Services District serves Jurupa Valley and surrounding areas in northwestern Riverside County. JCSD draws primarily from local groundwater in the Riverside Basin, which is influenced by geology rich in limestone and gypsum deposits.

JCSD's Consumer Confidence Report data shows total dissolved solids at approximately 350 parts per million. Eleven contaminants have been detected in JCSD's system, with eight exceeding health advocacy guidelines while remaining below enforceable legal limits. Those include arsenic, uranium, hexavalent chromium, trihalomethanes, nitrate, nitrite, selenium, and 1,1-dichloroethane.

Uranium is a naturally occurring radioactive contaminant in groundwater that receives less attention than arsenic or chromium but is present in portions of the Inland Empire groundwater supply. The federal MCL for uranium is 30 micrograms per liter. Reverse osmosis systems certified to NSF/ANSI Standard 58 reduce uranium from drinking water effectively. This contaminant profile underscores why a free water test in the Inland Empire before choosing treatment equipment is the right starting point.

For context on how Jurupa Valley's water compares to the San Bernardino County communities just to the north, see our analysis of PFAS in Inland Empire drinking water and the iron filter guide for San Bernardino County.

What do hard water and high TDS mean for Riverside County homes?

The practical effects of hard water and elevated TDS show up throughout the home, not just at the drinking tap. The two problems are related but distinct.

Hard water, defined by calcium and magnesium content, causes scale. Scale precipitates out of solution when water heats or evaporates, forming the white mineral crust on showerheads, faucet aerators, and glass shower enclosures. Inside water heaters, scale insulates the heating element from the water, forcing the unit to run longer and use more energy to reach temperature. The Water Quality Research Foundation, in research commissioned from Battelle Memorial Institute, found measurable efficiency loss in gas water heaters from hard water scale within the first year of use.

At 10 to 15 grains per gallon, scale accumulation in Riverside County homes is an ongoing process. At the higher TDS levels found in the Lake Elsinore area, the visible effects are even more pronounced because the dissolved mineral load is higher.

High TDS also affects drinking water palatability. Water above 500 ppm TDS often has a flat, mineral, or slightly salty character that many residents find unpleasant. The EPA's 500 ppm secondary standard for TDS exists specifically as a palatability benchmark.

The Inland Empire water filtration guide covers how different system types address these concerns at different points of the home.

Which water treatment systems address Riverside County water concerns?

The right system depends on which specific contaminants are present at your tap. Utility reports give district-wide averages. Your tap reading may be higher or lower based on your proximity to groundwater well inputs versus surface water blending points, your home's plumbing age, and your neighborhood's distribution zone.

For hardness: A water softener using ion exchange removes calcium and magnesium before water reaches any fixture in the home. This eliminates scale on appliances, fixtures, and pipes throughout the entire house. Water softeners in Temecula, water softeners in Murrieta, and water softeners in Riverside all address the same core problem with the same technology adapted to local hardness levels.

For drinking water contaminants (arsenic, uranium, chromium-6, TTHMs, TDS): A reverse osmosis system at the drinking tap is the most comprehensive point-of-use solution. RO systems certified to NSF/ANSI Standard 58 remove 90 to 99 percent of dissolved contaminants. Reverse osmosis systems in Temecula, reverse osmosis systems in Murrieta, and reverse osmosis systems in Riverside are available with NSF-certified units.

For both problems: A combination system pairs a whole-house water softener with a point-of-use RO unit. The softener handles hardness county-wide; the RO handles drinking water contaminants. Combo systems in Riverside and combo systems in Temecula package both into a single system.

We serve all five major Riverside County utility service areas and the entire county. Schedule a free water test in Corona or anywhere across the county to get your actual tap results before choosing equipment.

How do you find your own Riverside County utility's Consumer Confidence Report?

Every Riverside County resident can access their utility's annual CCR through two channels.

The first is your utility's website. Each utility listed in this article publishes its CCR online, typically in a "Water Quality" section. RCWD publishes at ranchowater.com. RPU publishes at riversideca.gov/utilities. EVMWD publishes at evmwd.com. EMWD publishes at emwd.org. JCSD publishes through the Jurupa Valley city website.

The second is the California SWRCB Electronic Annual Reporting database. Search by your water system name at waterboards.ca.gov and navigate to the Consumer Confidence Reports section.

Your CCR shows every contaminant tested, the level detected, the federal MCL, and whether the result was in compliance. It also shows the source of your water and the testing dates. This is the official public record, and it is updated annually.

For Orange County water quality data by utility, see our Orange County PFAS water data analysis. For LA County, see our Los Angeles County PFAS water data report.

If the CCR leaves you with questions about what the results mean for your home, a free water test in Riverside County translates the utility data into an actual tap-level reading. Call us at (949) 873-1129. We serve all of Riverside County and are familiar with the specific water quality challenges across RCWD, RPU, EVMWD, EMWD, and JCSD service areas.