Lead In Drinking Water In Colorado
What residents of Colorado need to know about lead in drinking water — including how it enters water, which utilities have documented violations, and what steps to take.
Source: EPA SDWIS, Colorado Department of Public Health and Environment (CDPHE), CDC · Last reviewed: 2025-01-01
Quick Answer
Is lead in drinking water a real concern in Colorado?
Yes — Denver has one of the most documented lead service line inventories among major U.S. cities, and the city launched an aggressive service line replacement program.
Is this mostly a public-water issue, a private-well issue, or both?
Both the public-side lead service line and household plumbing in pre-1951 homes; Denver's replacement program addresses the utility-side pipe, but homeowners remain responsible for their side of the connection.
What is the main reason residents should care?
Denver has tens of thousands of lead service lines identified in its distribution system. Denver Water launched a voluntary lead service line replacement program, but the process of full replacement will take years, and homes with lead service lines continue to face elevated risk in the interim.
Key Facts
| Federal Lead Action Level | 15 µg/L — no safe level per CDC |
| Denver LSL inventory | Thousands of lead service lines identified — active replacement program underway |
| Water chemistry | Snowmelt-sourced water is naturally soft and low-mineral — more corrosive |
| Denver Water tool | Service line lookup tool available to Denver Water customers |
| State oversight | Colorado Department of Public Health and Environment (CDPHE) |
Why This Matters in Colorado
Denver Water has publicly acknowledged that its service area includes a significant number of lead service lines — concentrated in older neighborhoods like Capitol Hill, Congress Park, Park Hill, Baker, and Curtis Park that were developed before lead service lines were banned. Denver Water launched a proactive lead service line replacement program and also offers free lead testing kits to customers. Colorado's snowmelt-fed water supply is naturally soft and low-mineral, which increases its corrosivity toward lead plumbing. CDPHE enforces the federal Lead and Copper Rule and requires utilities statewide to complete service line material inventories. Beyond Denver, Pueblo, Colorado Springs, and other older Colorado cities also have pre-1986 housing stock.
Historical Context
Denver Water publicly acknowledged thousands of lead service lines in its system and launched a customer-facing Lead Service Line Replacement Program, offering co-pay and full-replacement options. Denver's proactive public disclosure is one of the more transparent LSLR programs in the western U.S.
Colorado Utilities With Lead Violation Records
The utilities listed below have at least one lead violation on record in EPA's SDWIS database. Violations may be open or resolved — see individual utility pages for current status and risk level.
City of Thornton
Thornton · 226,465 served
City of Greeley
Greeley · 132,310 served
County of Broomfield City and
Broomfield · 106,153 served
Highlands Ranch Wsd
Highlands Ranch · 103,444 served
City of Loveland
Colorado · 95,471 served
Parker Wsd
Colorado · 75,949 served
City of Englewood
Colorado · 57,332 served
Clifton Wd
Colorado · 34,500 served
City of Aspen
Colorado · 31,100 served
Pueblo West Md
Pueblo · 30,000 served
How Lead Gets Into Drinking Water
Lead service lines
The pipe connecting a home to the water main may be made of lead, especially in pre-1986 construction. Water sitting in these lines can accumulate lead before it reaches the tap.
Lead solder
Lead solder at pipe joints was banned for potable water systems in 1986. Homes built before that date — including significant portions of older Colorado cities — may still have lead solder throughout their plumbing.
Older brass fixtures
Faucets, valves, and fixtures with high lead content were common before the 2014 revision of 'lead-free' standards. Replacing older fixtures at kitchen and drinking taps can meaningfully reduce exposure.
Corrosive water chemistry
Soft, acidic, or low-alkalinity water dissolves lead from plumbing more readily. Utilities use orthophosphate and other corrosion control treatments, but household plumbing after the meter is not within their control.
Who Should Pay Closest Attention
Denver residents in pre-1951 homes in older neighborhoods should check Denver Water's service line lookup tool. Families with children under six or pregnant residents in homes with a confirmed lead service line should use a certified NSF/ANSI 53 or 58 filter for drinking and cooking while awaiting replacement.
Families with children under six
Pregnant residents
Households in homes built before 1986
Renters who cannot inspect building plumbing
Residents on a confirmed lead service line
Households that had plumbing work done recently (disturbances dislodge protective scale)
How to Check Your Situation in Colorado
- 1
Identify your water utility. Use the ZIP lookup below or browse the Colorado utility directory on this site.
- 2
Read your utility's page on this site to see its current risk level and any open lead violations.
- 3
Contact your utility and ask for your address-level service line material status. Under the federal Lead and Copper Rule Revisions (LCRR), utilities must maintain and provide this information.
- 4
Review your utility's most recent Consumer Confidence Report (CCR) — mailed annually or available on the utility's website.
- 5
Consider testing your tap water at a Colorado Department of Public Health and Environment (CDPHE)-certified lab. Your state health department or Colorado Department of Public Health and Environment (CDPHE) maintains a list of certified labs.
- 6
If you have young children or are pregnant, install a certified NSF/ANSI 53 or 58 filter at the kitchen tap as a precautionary measure.
Treatment Options
Boiling does not remove lead. Use a certified filter for drinking and cooking water.
NSF/ANSI Standard 53 — Activated Carbon Block
Under-sink or pitcher filters certified to Standard 53 are independently verified to reduce lead. Replace filters on the manufacturer's schedule — an overdue filter may not perform as certified.
NSF/ANSI Standard 58 — Reverse Osmosis
RO systems certified to Standard 58 remove 95–99% of lead and a broad range of contaminants. Requires under-sink installation. More comprehensive than Standard 53 for households with multiple contaminant concerns.
Flushing — temporary mitigation only
EPA recommends flushing the cold tap for 30 seconds to 2 minutes if water has sat in pipes for 6+ hours. Not a substitute for certified filtration or service line replacement.
Frequently Asked Questions
Related Pages
Lead — National Overview
All U.S. utilities with lead records
Colorado State Overview
All utilities and water quality data
Nitrate in Drinking Water
A separate but common concern
Reverse Osmosis Guide
Removes 95–99% of lead
Activated Carbon Filter Guide
NSF/ANSI 53 certified options
All Contaminants
Complete reference library
Data Sources & Provenance
All data on this page is sourced from official U.S. government or public datasets.