Is South Fork, CO Tap Water Safe to Drink?
Graded D — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
46/100
waterverge.com South Fork, CO — Water Quality Report
South Fork's drinking water received a grade of D (46 out of 100), indicating poor water quality. The city's 4 water systems serve approximately 1,152 residents using groundwater.
Lead levels were measured at 1.5 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 255 violations on record, including 8 health-based violations. 26 remain unresolved.
What to know about South Fork's water
South Fork ranks #196 out of 246 cities in Colorado for water quality, placing it among the lowest-rated in the state.
South Fork relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
As a small community water system, South Fork may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 107 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is South Fork, CO water safe to drink?
South Fork's drinking water has significant quality concerns based on EPA testing data. With a grade of D (46/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 4 water systems serve approximately 1,152 residents using groundwater (wells).
Recent water quality updates for South Fork
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into South Fork's water quality assessment. Grade: D (46/100).
Contaminants: Surface Water Treatment Rule.
Contaminants: Gross Alpha, Excl. Radon and U, Combined Uranium, Combined Radium (-226 and -228).
Contaminants: Lead and Copper Rule.
Federal disaster declaration (FEMA DR-3224). Coastal Storm event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-396). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for South Fork's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
South Fork's water system has 255 total violations on record, including 8 health-based violations. 26 remain unresolved. 107 violations were issued in the last 5 years.
Flood & environmental risk
Rio Grande County has experienced 3 federally declared disasters since 1970. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does South Fork's water come from?
South Fork's drinking water comes from groundwater (wells), supplied by 4 water systems serving approximately 1,152 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What South Fork residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in South Fork's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
South Fork's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Drought conditions
D3 — extreme droughtRio Grande County is currently in D3 (extreme drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Rio Grande County has experienced 3 federally declared disasters since 1970. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in South Fork's water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 1.5 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.90 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how South Fork compares by contaminant
Explore where South Fork ranks among all Colorado cities for specific contaminants.
Water source & infrastructure
Where South Fork's water comes from
South Fork's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by local government ownership and serves approximately 1,152 people through 4 water systems.
Water systems serving South Fork
| System Name | PWSID | Population | Source |
|---|---|---|---|
| SOUTH FORK WEST MUNICIPAL TOWN OF | CO0253718 | 566 | GW |
| RIO GRANDE WATER COMPANY | CO0253860 | 265 | GU |
| RIVIERE ESTATES | CO0253690 | 211 | GW |
| INDIAN TRAILS WATER LLC | CO0153450 | 110 | GW |
How South Fork compares
Full Colorado rankings →South Fork's score of 46/100 is on par with the average of 45/100 among major Colorado cities. It outscores 7 of 10 nearby cities.
Nearby cities
View Colorado rankings →About South Fork, CO
Wikipedia →South Fork is a statutory town in Rio Grande County, Colorado, United States. It lies at the confluence of the South Fork and Rio Grande rivers. The population was 510 at the 2020 census.
Learn more about your water
Guides and resources related to South Fork's water quality findings.
Explore water quality across Rio Grande
Frequently asked questions
Is South Fork, CO tap water safe to drink?
South Fork's water quality earned a grade of D (46/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #196 out of 246 cities tested in Colorado.
What contaminants are in South Fork's water?
Lead was measured at 1.5 ppb (90th percentile). 255 violations are on record.
How is South Fork's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in South Fork?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does South Fork's water come from?
South Fork's water is sourced from Groundwater. The city has 4 water systems serving approximately 1,152 residents.
What health violations has South Fork's water system had?
South Fork has 8 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 26 violations remain unresolved.
Is South Fork's groundwater at risk of contamination?
South Fork uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 255 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does South Fork's water compare to other cities?
South Fork ranks #196 out of 246 cities in Colorado (better than 20% of state cities) and #14055 out of 15744 cities nationally (11th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.