What's in Rancho Cucamonga's Tap Water, and Why We Filter It

Cucamonga Valley Water District delivers water that meets EPA standards. It's treated for safety. But meeting safe limits and producing water that's optimal for daily drinking are two different things. Here's what the water contains, and what we do to it before it goes into your jug.

Where the Water Comes From

Cucamonga Valley Water District (CVWD) is the primary water provider for Rancho Cucamonga. The district sources water from a combination of local groundwater (from the Chino Basin), imported water from the State Water Project and Colorado River, and recycled water for irrigation.

The district publishes an annual water quality report. The report shows the water meets all federal and state standards. What it also shows, and what people often don't read closely, is what's actually in the water within those compliance ranges.

What's in the Water

Standard municipal water treatment adds disinfectants and leaves behind treatment byproducts. In Rancho Cucamonga's supply, you'll typically find:

Chlorine and chloramines. Used for disinfection during distribution. They're effective at preventing waterborne illness through the pipe network. But chlorine produces trihalomethanes (THMs) as a byproduct when it reacts with organic matter, and chloramines produce related haloacetic acids. Both are regulated and kept within limits, but limits aren't zero.

Naturally occurring minerals. The local groundwater is moderately hard, containing dissolved calcium, magnesium, and some iron. Hard water is not a health risk, but it affects taste and total dissolved solids (TDS).

PFAS. Per- and polyfluoroalkyl substances have been detected in groundwater across the Inland Empire, including in basins that CVWD draws from. PFAS contamination is widespread in Southern California due to historical use of AFFF firefighting foam at nearby military installations and airports. CVWD has invested in treatment infrastructure to address PFAS, but detection in source water is a documented fact.

Fluoride. Added by the district at low concentrations as a dental health measure. Compliance is within state limits.

Trace heavy metals. Lead is not added by the utility — it can enter water from aging pipes between the main and your tap. In older Inland Empire neighborhoods, the pipe infrastructure varies. The utility tests at the entry point, not at your tap.

What Our 9-Stage System Does to It

Every gallon we produce — RO, alkaline, or Kangen — starts with CVWD tap water and goes through our full 9-stage AMPAC commercial filtration system before anything else happens.

The system removes:

• Chlorine and chloramines, in the multimedia carbon pre-filter and carbon block stages
• Calcium, magnesium, lead, and iron, in the ion exchange softener stage
• Suspended solids, in the pre-filter and sediment stages (25 micron down to 20 micron and 5 micron)
• Fluoride, PFAS, heavy metals, and dissolved solids, in the TFC high-flow reverse osmosis membrane stage
• Residual taste and odor, in the Big Blue carbon post-filter
• Microorganisms, in the stainless steel UV sterilizer at the point of fill
• Shelf-life degradation, managed by the ozone generator system in storage

After that, depending on which water type you're filling:

• RO (7.0 pH): nothing added, pure, neutral output
• Alkaline 8.5 or 9.5 pH: controlled mineral re-addition (calcium, magnesium, potassium)
• Kangen: post-filtration electrolysis on a medical-grade Enagic machine

The Short Version

The tap water in Rancho Cucamonga is safe by legal definition. It's treated professionally by CVWD. But it still contains disinfection chemicals, treatment byproducts, and trace contaminants within permitted ranges. Our system starts from that water and removes what you'd want removed before it reaches your container.

The result is measurably different from tap. Most customers notice it in the first glass — no chlorine aftertaste, cleaner finish, different mouthfeel depending on which type you choose.