Seville Water Company

Visalia, CA · serves 691 · GroundwaterCA5400550
Action recommended
This system has an open, unresolved health-based violation for Lead and Copper. Check your utility's notification or use bottled water until the violation is resolved.
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Measured in your 2023 water report
From your utility's Consumer Confidence Report · 19 contaminants tested
Above limit
Approaching limit
Within limits
Regulated contaminants — legally enforceable limits
Fluoride
0.1 mg/L
Reference: MCL
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
Naturally occurring mineral, also added to many water systems to prevent tooth decay. The MCL (4 mg/L) is much higher than the typical added amount (0.7 mg/L).
Why it matters
At levels near the MCL, long-term exposure can cause skeletal fluorosis (bone pain and tenderness). The secondary standard of 2 mg/L triggers a required public notice about dental fluorosis risk in children.
What to do
Levels below 2 mg/L are within the range considered safe. If above 2 mg/L, children under 9 may be at risk for dental fluorosis — talk to your pediatric dentist.
What the research says
Multiple peer-reviewed studies have found lower IQ in children and potential thyroid disruption at concentrations as low as 1.5 mg/L3x below the US federal limit.
Gross Alpha
1.02 pCi/L
Reference: MCL
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
A screening test that measures total alpha radiation from all radioactive elements in water — including radium, uranium, and radon.
Why it matters
The MCL of 15 pCi/L protects against long-term cancer risk from radiation exposure.
What to do
No action needed at typical detection levels. If near the MCL, reverse osmosis and ion exchange filters can reduce radioactive contaminants.
Nitrate (as N)
6.3 mg/L
Reference: MCL
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
Comes from fertilizer runoff, septic systems, and erosion of natural deposits. One of the most common groundwater contaminants in agricultural areas.
Why it matters
Nitrate above 10 mg/L can cause "blue baby syndrome" (methemoglobinemia) in infants under 6 months — it interferes with blood's ability to carry oxygen. Adults can tolerate higher levels.
What to do
If you have an infant on formula and your water is above 5 mg/L, consider using bottled water for formula preparation. Boiling water does NOT remove nitrate — it concentrates it.
What the research says
Multiple peer-reviewed studies have found neural tube defects, preterm birth, and low birth weight at concentrations as low as 5 mg/L2x below the US federal limit.
Nitrate + Nitrite (as N)
6.7 mg/L
Reference: MCL
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
No additional information available for this contaminant.
Disinfection byproducts
HAA5
3 µg/L
Reference: MCL
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
Another group of disinfection byproducts formed when chlorine reacts with natural organic matter. HAA5 measures the five most common species.
Why it matters
Long-term exposure above the MCL of 60 µg/L (0.060 mg/L) is associated with increased cancer risk. Like THMs, the MCL is based on a running annual average.
What to do
Activated carbon filters can reduce HAA5. If your system consistently approaches the limit, a reverse osmosis filter provides more complete removal.
TTHM
7 µg/L
Reference: MCL
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
Formed when chlorine used to disinfect water reacts with natural organic matter. Includes chloroform, bromoform, and related compounds. The trade-off: disinfection prevents waterborne disease, but creates these byproducts.
Why it matters
Long-term exposure above the MCL of 80 µg/L (0.080 mg/L) is associated with increased cancer risk and possible reproductive effects. The MCL is based on a running annual average, not a single sample.
What to do
If your system is near or above the limit, an activated carbon filter (including pitcher filters like Brita) can reduce THMs. Running water for a minute before drinking also helps, as THMs are volatile and dissipate.
WHO recommendation
Manganese
0.015 mg/L
Reference: WHO guideline
World Health Organization drinking-water guideline. International guidance, not legally enforced in the US.
What is it?
A naturally occurring metal that enters water through eroding rocks and soils, and occasionally from industrial sources. Common in groundwater, especially in some regions of the Midwest and Northeast.
Why it matters
Manganese is essential in small amounts but a developmental neurotoxin at higher exposures. Studies have linked manganese in drinking water to attention and learning difficulties in children, including ADHD, with effects detectable at levels below the EPA's aesthetic standard of 0.05 mg/L. The WHO sets a provisional health-based guideline of 0.08 mg/L; some researchers argue this should be lower. Infants drinking formula made with manganese-rich water may be particularly exposed. EPA's 0.05 mg/L secondary standard exists to prevent black or brown staining on laundry and fixtures — not as a health protection.
What to do
If manganese is at or near WHO's 0.08 mg/L guideline, a reverse osmosis filter certified to NSF/ANSI 58 removes most manganese. Activated carbon and standard pitcher filters do not effectively remove dissolved manganese. For infant formula preparation, parents in areas with detectable manganese may want to use filtered or bottled water — this is what MDH (Minnesota) and several other state health departments now recommend.
What the research says
Multiple peer-reviewed studies have found increased ADHD risk and lower IQ in children, with effects observed in a dose-response pattern from <5 µg/L upward (no clean threshold below which the association disappears) with a dose-response relationship across the range of concentrations found in drinking water.
Sodium
40 mg/L
Reference: WHO guideline
World Health Organization drinking-water guideline. International guidance, not legally enforced in the US.
What is it?
Naturally present in most water sources. Also increases from road salt, water softeners, and natural mineral deposits.
Why it matters
There is no federal MCL for sodium. The WHO suggests a guideline of 200 mg/L for people on sodium-restricted diets. For most people, sodium in water is a small fraction of dietary intake.
What to do
If you're on a sodium-restricted diet and your water is above 20 mg/L, talk to your doctor. For most people, no action needed.
% of limit

Other measurements

These describe characteristics of the water that aren’t health risks at typical levels — mineral content, taste, hardness, and similar.

Hardness
157 mg/L· hard
pH
6.86 SU· neutral
Alkalinity
135 mg/L
Calcium
39 mg/L
Chloride
63 mg/L
(EPA secondary standard: 250 mg/L)
LSI
11
Magnesium
15 mg/L
Specific Conductance
540 µmhos/cm
(EPA secondary standard: 1600 µmhos/cm)
Sulfate
17.4 mg/L
(EPA secondary standard: 250 mg/L)
TDS
330 mg/L
(EPA secondary standard: 500 mg/L)
Vanadium
52 µg/L

CCR data in early access — values are extracted from utility PDFs and may contain errors. Verify with your utility's 2023 CCR report.

Source: SEVILLE WATER COMPANY Consumer Confidence Report 2023 · Extracted by WaterScore
Measured data
Private Well Risk

Do you have or use a private well? Measured concentrations from nearby private wells sampled within 5 miles.

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2 wells
Water Sources

Visalia pumps water from two groundwater wells drawing from the Central Valley aquifer system.

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