Water Quality: Des Peres, TX

Increases blood pressure and causes cardiovascular effects with long-term exposure.

Common source: Natural rock deposits, oil drilling operations, coal power plant waste

EPA limit: 2 mg/L

Probable human carcinogen that increases the risk of kidney and thyroid cancers.

Common source: Ozonation of bromide-containing water; used as flour improver

EPA limit: 0.010 mg/L (10 ppb)

Can cause anemia in infants and young children; may cause nervous system effects at high levels.

Common source: Water treatment disinfectant used to control taste, odor, and microorganisms

EPA limit: 0.8 mg/L

Broad category of chemicals formed during disinfection, associated with increased cancer risk and adverse reproductive effects.

Common source: Reaction of disinfectants (chlorine, ozone, chloramines) with organic matter

Causes gastrointestinal illness; certain strains (e.g., O157:H7) can cause severe kidney failure and death.

Common source: Fecal contamination from humans or animals entering the water supply

EPA limit: Zero (no E. coli permitted in drinking water)

Indicates direct fecal contamination; associated with diarrhea, cramps, nausea, and potential severe illness.

Common source: Human and animal fecal waste

EPA limit: Zero tolerance (any positive triggers violations)

At low levels prevents tooth decay; excessive levels cause dental and skeletal fluorosis.

Common source: Natural deposits, water fluoridation programs, some fertilizers

EPA limit: 4.0 mg/L (secondary standard: 2.0 mg/L)

Alpha-emitting radioactive particles increase cancer risk, particularly from bone and other internal cancers.

Common source: Natural uranium and radium in geological formations

EPA limit: 15 pCi/L (excluding radon and uranium)

Haloacetic acids are associated with increased cancer risk and potential reproductive and developmental effects.

Common source: Reaction of chlorine disinfectants with organic matter in treated water

EPA limit: 0.060 mg/L (60 ppb)

Causes neurological damage, developmental delays in children, and kidney damage in adults even at low exposure levels.

Common source: Old plumbing pipes, lead solder, brass fixtures

EPA limit: Action Level: 0.015 mg/L (15 ppb)

Hair loss, nail brittleness, and nervous system damage at elevated concentrations.

Common source: Natural geological deposits, mining discharges, oil refinery waste

EPA limit: 0.05 mg/L (50 ppb)

Trihalomethanes and haloacetic acids that increase cancer risk and may cause adverse reproductive outcomes.

Common source: Chlorine disinfection reacting with natural organic matter in source water

EPA limit: TTHM: 0.080 mg/L; HAA5: 0.060 mg/L

Total trihalomethanes are linked to increased risk of bladder cancer and adverse reproductive outcomes.

Common source: Reaction of chlorine disinfectants with naturally occurring organic matter in water

EPA limit: 0.080 mg/L (80 ppb)

Haloacetic acids are associated with increased cancer risk and potential reproductive and developmental effects.

Common source: Reaction of chlorine disinfectants with organic matter in treated water

EPA limit: 0.060 mg/L (60 ppb)

Not a direct health risk but reacts with disinfectants to form carcinogenic byproducts such as trihalomethanes.

Common source: Decaying plant material, algae, soil organic matter in source water

EPA limit: Treatment technique (must reduce TOC based on source water level)