C50/100
Custer Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 1,919 residents · South Dakota
What's In Custer's Tap Water?
2
Contaminants Tested
1
Exceed EPA Limits
1
Above EPA Goals
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.50 mg/L | 1.30 mg/L | Over Limit |
Lead (90th percentile) | 0.002 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 1998.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
CUSTER
Population Served
1,919
Water Source
Groundwater
System ID
SD4600101
Frequently Asked Questions About Custer Water
Is Custer tap water safe to drink?
Custer, South Dakota tap water receives a grade of C (50/100), which is considered fair. 1 contaminant(s) exceed EPA maximum contaminant levels and 39 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Custer's water?
Of the 2 contaminants tested in Custer's water supply, the most notable include Copper (90th percentile), Lead (90th percentile). 1 contaminant(s) exceed EPA legal limits (MCLs). 2 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Custer have any water quality violations?
Yes, Custer has 39 EPA violation(s) on record, with the most recent in 1998. Violation types include MR. None of these are classified as health-based violations.
Do I need a water filter in Custer?
Based on EPA data, using a water filter in Custer is recommended. 1 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.
Where does Custer's tap water come from?
Custer's drinking water is sourced from groundwater and supplied by CUSTER. The system serves approximately 1,919 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Custer's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Custer's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Custer's water compare to other cities in South Dakota?
Custer's water quality score of 50/100 earns a grade of C, which is considered fair. This is a below-average score that indicates room for improvement. Visit our South Dakota state page to see how all cities in the state compare.
What should I do if I'm concerned about Custer's water quality?
If you have concerns about Custer's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (CUSTER) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.