← Back to search

Harris County MUD 238

The Woodlands, TX · serves 7,773 · Purchased surface waterTX1012361
Worth watching
Naturally occurring lithium detected. No federal limit. Research is preliminary; see the lithium learn page for context.
See filter recommendations →
Not your system? Search your address:
Measured in your 2025 water report
From your utility's Consumer Confidence Report · 14 contaminants tested
⚠
Contaminants detected above federal limits
Your utility's own 2025 water report disclosed the following levels. Utilities have until 2029 to comply with new federal limits.
ContaminantDetected LevelFederal LimitHow Far Over
Gross Alpha17.5 pCi/L15 pCi/L~1.2× the limit
Above limit
Approaching limit
Within limits
Regulated contaminants — legally enforceable limits
Atrazine▸
0.00013 mg/L
Reference: MCL
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
One of the most widely used agricultural herbicides in the US. Enters groundwater and surface water from cropland runoff, especially in the Midwest corn belt.
Why it matters
The MCL of 0.003 mg/L protects against cardiovascular and reproductive effects. Atrazine is also an endocrine disruptor at very low levels.
What to do
Activated carbon filters can reduce atrazine. If you're in an agricultural area with detections near the MCL, a point-of-use filter is good protection.
Barium▸
0.05 mg/L
Reference: MCL
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
A naturally occurring metal found in mineral deposits. Enters water through erosion of natural deposits or discharge from drilling and metal refining operations.
Why it matters
At high levels, barium can cause increased blood pressure. Levels well below the MCL of 2 mg/L are not a health concern.
What to do
No action needed at typical detection levels. Barium is rarely found near its MCL in treated drinking water.
Combined Radium▸
4.1 pCi/L
Reference: MCL
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
The combined measurement of radium-226 and radium-228 — naturally occurring radioactive elements found in some groundwater, especially in the Midwest and Great Plains.
Why it matters
Long-term exposure above the MCL of 5 pCi/L increases cancer risk, particularly bone cancer. Radium is most common in deep groundwater wells.
What to do
Ion exchange water softeners can reduce radium. Reverse osmosis is also effective. If your system uses groundwater and radium is detected, a point-of-use filter adds a layer of protection.
Fluoride▸
0.27 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/L — 3x below the US federal limit.
Gross Alpha▸
17.5 pCi/L ×1.2
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)▸
0.95 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/L — 2x below the US federal limit.
Radium-226▸
4.1 pCi/L
Reference: MCL
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
What is it?
A naturally occurring radioactive element produced by the decay of uranium in rock and soil. Most common in deep groundwater.
Why it matters
Combined radium (226 + 228) has an MCL of 5 pCi/L. Radium-226 is an alpha emitter linked to bone cancer with long-term exposure.
What to do
Ion exchange and reverse osmosis filters are effective at reducing radium.
Simazine▸
0.00007 mg/L
Reference: MCL
Federal Maximum Contaminant Level. The legally enforceable EPA drinking-water standard.
No additional information available for this contaminant.
Lead & copper — tested at your tap
Copper▸
0.0947 mg/L
Reference: Action level
Federal Lead and Copper Rule action level. Legally enforceable. Exceeding it triggers required corrective action by the utility.
What is it?
Leaches from copper household plumbing and pipes. Some copper is a normal part of drinking water infrastructure.
Why it matters
Short-term exposure above the action level of 1.3 mg/L can cause gastrointestinal distress. Long-term exposure can cause liver and kidney damage. At typical detected levels (well below the AL), copper is not a health concern.
What to do
If above the action level, run your tap for 30 seconds before drinking. Copper levels decrease as water flows through the pipes.
Lead▸
0.000534 mg/L
Reference: Action level
Federal Lead and Copper Rule action level. Legally enforceable. Exceeding it triggers required corrective action by the utility.
What is it?
Lead in drinking water almost always comes from your home's plumbing — not from the water source or treatment plant. Lead pipes, solder, and brass fixtures can leach lead, especially if water sits in pipes for hours.
Why it matters
There is no safe level of lead exposure. Even low levels can harm children's brain development, and cause kidney and blood pressure problems in adults. The action level of 15 µg/L is a regulatory trigger, not a safety threshold.
What to do
Run your tap for 30 seconds to 2 minutes before drinking, especially in the morning. Use cold water for cooking and formula — hot water leaches more lead. A filter certified to NSF/ANSI 53 for lead removal is the most reliable protection.
What the research says
There is no safe level of lead exposure. Lead crosses the placenta and causes preterm birth and cognitive impairment in children at blood lead levels below 10 µg/dL.
Disinfection byproducts
HAA5▸
34 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.
DBCM▸
3.9 µg/L
Reference: MCLG
Maximum Contaminant Level Goal. A non-enforceable EPA health goal, set at the concentration where no known or anticipated adverse health effect would occur. The legally enforceable standard for this contaminant lives at the parent-group level (e.g. TTHM, HAA5), not on the individual species.
What is it?
A brominated trihalomethane formed when chlorine reacts with bromide-containing organic matter. More common in source waters with higher bromide levels — often coastal or groundwater systems.
Why it matters
EPA sets the MCLG at 0.06 mg/L based on liver and kidney effects. Some evidence suggests DBCM may be carcinogenic, though the data is less clear than for BDCM and bromoform. Regulated together with the other three trihalomethanes under TTHM.
What to do
Like other THMs, DBCM forms in the distribution system as chlorine reacts over time. A point-of-use carbon-block filter (NSF/ANSI 53) reduces it along with related compounds.
TTHM▸
39 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
Nickel▸
0.0018 mg/L
Reference: WHO guideline
World Health Organization drinking-water guideline. International guidance, not legally enforced in the US.
What is it?
A metal that enters water from natural deposits and industrial discharge. The federal MCL was remanded (withdrawn) in 1995 but monitoring continues.
Why it matters
No current federal MCL. At typical detection levels, nickel in drinking water is not considered a health concern for most people. People with nickel allergies may be more sensitive.
What to do
No action needed at typical detection levels.
% of limit

CCR data in early access — values are extracted from utility PDFs and may contain errors. Verify with your utility's 2025 CCR report.

Source: HARRIS COUNTY MUD 238 Consumer Confidence Report 2025 · 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.

Details ↓
Blended supply
Water Sources

The Woodlands uses both groundwater and surface water sources, giving it more supply flexibility during drought conditions. Emergency backup sources are available if primary supplies are disrupted.

Details ↓
Spatial context
Your area on the map
Open full map →