Is Sherwood, WI Tap Water Safe to Drink?
Graded B- — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
72.3/100
waterverge.com Sherwood, WI — Water Quality Report
Sherwood's drinking water received a grade of B- (72.3 out of 100), indicating fair water quality. The city's 1 water system serves approximately 3,114 residents using purchased surface water.
Lead levels were measured at 0.0 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 38 violations on record, including 12 health-based violations. 18 remain unresolved.
What to know about Sherwood's water
Sherwood ranks #339 out of 446 cities in Wisconsin for water quality, placing it among the lowest-rated in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
As a small community water system, Sherwood may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Sherwood, WI water safe to drink?
Sherwood's drinking water has significant quality concerns based on EPA testing data. With a grade of B- (72.3/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 3,114 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Sherwood
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Sherwood's water quality assessment. Grade: B- (72.3/100).
Contaminants: TTHM, Total Haloacetic Acids (HAA5).
1 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS, Public Notice, Consumer Confidence Rule.
Contaminants: Total Haloacetic Acids (HAA5), TTHM.
Federal disaster declaration (FEMA DR-3249). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-1369). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Sherwood'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
Sherwood's water system has 38 total violations on record, including 12 health-based violations. 18 remain unresolved. 5 violations were issued in the last 5 years.
Flood & environmental risk
Calumet County has experienced 3 federally declared disasters since 1976. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Lake Winnebago, Fox River, Fox R.
Where does Sherwood's water come from?
Sherwood's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 3,114 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Lake Winnebago (lake), Fox River (river), Fox R (river).
What Sherwood residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Sherwood'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.
Sherwood'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
Top industrial polluters within 10 miles of Sherwood
Industrial polluters nearby
Reported releases to surface water by facilities near Sherwood, ranked by pounds discharged annually.
Total reported releases to surface water: 33,929 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
AHLSTROM NA SPECIALTY SOLUTIONS LLC KAUKAUNA, WI54130 | Manganese And Manganese Compounds | 24,220 | 7.2 mi |
MCKINLEY PAPER & PACKAGING CO COMBINED LOCKS, WI54113 | Ammonia | 8,391 | 6.6 mi |
BELGIOIOSO SHERWOOD MENASHA, WI54952 | Nitrate compounds (water dissociable; reportable only when in aqueous solution) | 750 | 1.6 mi |
ESSITY PROFESSIONAL HYGIENE N.A. LLC MENASHA, WI54952 | Ammonia | 306 | 9.0 mi |
NEENAH FOUNDRY CO NEENAH OPERATIONS NEENAH, WI54956 | Manganese | 262 | 9.9 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Sherwood
Superfund sites nearby
Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
- SCHMALZ DUMP6.4 mi
- N W MAUTHE CO INC9.4 mi
Source: EPA Superfund National Priorities List
Flood & disaster history
Calumet County has experienced 3 federally declared disasters since 1976. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Sherwood'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. | 0.0 | 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. | 1.80 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 1.800 mg/L (1993)
EPA action level: 1.3 mg/L
See how Sherwood compares by contaminant
Explore where Sherwood ranks among all Wisconsin cities for specific contaminants.
Water source & infrastructure
Where Sherwood's water comes from
Sherwood's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by local government ownership and serves approximately 3,114 people through 1 water system.
Water bodies near Sherwood
Sherwood is located near 3 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Sherwood
| System Name | PWSID | Population | Source |
|---|---|---|---|
| SHERWOOD WATERWORKS | WI4080271 | 3,114 | SWP |
How Sherwood compares
Full Wisconsin rankings →Sherwood's score of 72.3/100 is above the average of 65/100 among major Wisconsin cities. It outscores 6 of 10 nearby cities.
Nearby cities
View Wisconsin rankings →About Sherwood, WI
Learn more about your water
Guides and resources related to Sherwood's water quality findings.
Explore water quality across Calumet
Frequently asked questions
Is Sherwood, WI tap water safe to drink?
Sherwood's water quality earned a grade of B- (72.3/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #339 out of 446 cities tested in Wisconsin.
What contaminants are in Sherwood's water?
Lead was measured at 0.0 ppb (90th percentile). 38 violations are on record.
How is Sherwood'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 Sherwood?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Sherwood's water come from?
Sherwood's water is sourced from Purchased surface water. The city has 1 water system serving approximately 3,114 residents.
What health violations has Sherwood's water system had?
Sherwood has 12 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. 18 violations remain unresolved.
How does Sherwood's water compare to other cities?
Sherwood ranks #339 out of 446 cities in Wisconsin (better than 24% of state cities) and #10390 out of 15744 cities nationally (34th percentile). The grade of B- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Sherwood's small water system affect quality?
Sherwood's system serves approximately 3,114 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 38 violations on record.