A91/100
Groton Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 1,380 residents · South Dakota
What's In Groton's Tap Water?
1
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.003 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
1
Violation (last 5yr)
0
Unresolved
0
Health-Related
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: April 1, 2023 – June 30, 2023Rule: Stage 1 DBPREnforcement: Resolving — corrective action underway
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
GROTON
Population Served
1,380
Water Source
Purchased Surface Water
System ID
SD4600147
Frequently Asked Questions About Groton Water
Is Groton tap water safe to drink?
Groton, South Dakota tap water receives a grade of A (91/100), which is considered excellent. Out of 1 contaminants tested, none exceed EPA maximum contaminant levels (MCLs) and 1 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Groton's water?
Of the 1 contaminants tested in Groton's water supply, the most notable include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Groton have any water quality violations?
Yes, Groton has 6 EPA violation(s) on record, with the most recent in 2023. Violation types include MR. None of these are classified as health-based violations.
Do I need a water filter in Groton?
Groton water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 1 contaminant(s) exceed these stricter goals.
Where does Groton's tap water come from?
Groton's drinking water is sourced from purchased surface water and supplied by GROTON. The system serves approximately 1,380 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Groton'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. Groton'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 Groton's water compare to other cities in South Dakota?
Groton's water quality score of 91/100 earns a grade of A, which is considered excellent. This places Groton among the better-performing water systems in South Dakota. Visit our South Dakota state page to see how all cities in the state compare.
What should I do if I'm concerned about Groton's water quality?
If you have concerns about Groton'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 (GROTON) 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.