Colby, KS: High Radon Risk — 70/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
Drinking water tracked for Colby by KS authorities posts above-average scores — the majority of systems are free from health-based exceedances and the city's grade sits above the state median.
How Colby Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Colby Water
- Average lead level: 0.0013 mg/L.
- Homes built before 1986: 79% — older plumbing may contain lead solder.
- Estimated remediation: $3,000 per household.
- CDC health risk index: 12.33 — above typical levels.
Who Supplies Your Water in Colby
Water service in Colby, KS is organized around a single utility — one of 1 tracked by regulator, and the one that manages the local distribution network while holding primary responsibility for EPA compliance reporting.
Overview
We track water quality and home safety data for 1 ZIP code in Colby, Kansas, covering 1 community water system serving approximately 6,166 people.
No EPA violations recorded across any ZIP codes in Colby — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Colby: B (70/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Colby water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0013 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 67701 | B | City of Colby, | 5,516 |
All ZIP Codes in Colby
- 67701 [B]
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
Health Outcomes in Colby
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Housing & Infrastructure in Colby
With 79% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
The median home in Colby was built in 1961 — a figure that places most of the city's residential stock in the era when lead solder was still standard in copper plumbing. Homes built before 1986 may have lead-soldered joints; those built before 1970 face the additional possibility of lead pipes in the service line itself.
Over half of homes in Colby were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
Cost Context: What Remediation Means for Colby Homeowners
The cost-to-value ratio in Colby is in the moderate range — neither dismissible nor alarming, but above the threshold where remediation can be treated as incidental. Most homeowners here are weighing a real equity commitment, and the moderate classification reflects that accurately.
Remediation costs are moderate relative to home values in Colby. The estimated $2,000–$4,000 range is manageable for most homeowners but still worth budgeting for. Home values are 10% above the Kansas average.
Lead Exposure Risk for Children in Colby
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Despite citywide averages serving as the standard public reference point, those aggregates cannot resolve what is happening at one specific faucet — and where 79% of Colby homes come from before the solder rule or where utility samples sit at or above the action mark, the gap between system data and faucet reality matters more than it does in lower-exposure communities. An in-home draw closes that gap, with certified filtration through retailer networks available where confirmed faucet results warrant additional measures.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Colby
The NFIP claim record for Colby — 3 filed incidents — reflects genuine, recurring flood exposure rather than an isolated event or two. When a community accumulates flood claims at this volume and carries 100% of its ZIP codes inside FEMA-designated zones, flood history starts to factor into water quality planning in ways it doesn't for lower-exposure areas. Flooding introduces specific contamination pathways — runoff overwhelming treatment facility intake, surface water infiltrating private wells, and pressure disruptions in distribution systems allowing backflow — all of which become more relevant as flood frequency increases.
Colby has a moderate flood history with 3 FEMA claims. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$3,000</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
Deep Dive Reports
Detailed analysis for Colby, KS