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Denver Water’s Lead Reduction Program Plan submitted to EPA

DENVER — Sept. 10, 2019— On Friday, Sept. 6, 2019, Denver Water submitted its Lead Reduction Program Plan to the Environmental Protection Agency and has opened a public comment period on the plan until Oct. 10.

The plan is a more holistic and cost-effective option than adding orthophosphate to drinking water in March 2020 — which is the current mandate from the Colorado Department of Public Health and Environment to reduce the risk of lead in tap water for homes with lead plumbing and service lines.

All comments will be provided to EPA and CDPHE for consideration as they determine the final course of action. A decision is expected to be made by the end of 2019. To view the executive summary and provide a comment, visit Lead Reduction Program Plan Feedback.

“Denver Water is proposing this holistic approach because we believe it is most protective of future generations and is in the best interest of public health and the environment,” said Denver Water CEO/Manager Jim Lochhead. “By tackling the issue at its source, our plan will eliminate lead service lines — the most significant source of lead in tap water — within 15 years and have fewer impacts to rivers, streams and reservoirs.”

Lead service lines
Lead service lines, like the ones pictured here, were initially installed by builders most likely before 1951 and are owned by customers.

The water delivered to homes and businesses in Denver is lead-free, but lead can get into water as it moves through lead-containing household plumbing and service lines that are owned by the customer and are not part of Denver Water’s system.

The proposed program includes replacing all customer lead service lines to remove the most significant source of potential lead entering drinking water, and further increasing the pH level of the drinking water to help prevent corrosion from homes with lead fixtures and pipes with lead solder. As part of this program, Denver Water also would provide at-home water filters to all Denver Water customers suspected of having a lead service line, free of charge, until the lead service line is removed by Denver Water.

While costs are still being reviewed, the current financial impact of adding orthophosphate is estimated to be much greater to the region than Denver Water’s proposal. The regional cost impacts related to orthophosphate is estimated to be between $480 million and $714 million and the variance proposal is estimated to cost between $304 million and $556 million.

Drawbacks to Denver Water using orthophosphate include the ripple effects of adding this nutrient into the larger water supply that can, under the right conditions, set off a chain of problematic events, such as accelerating the growth of algae in area lakes, reservoirs and ponds.

Denver Water incorporated feedback from a public comment period on the draft plan into its final proposal. Of the more than 400 respondents who commented, 98% indicated that they support the plan, emphasizing benefits for future generations, environmental health and protecting infants and children. See the full results from the comment period.

For nearly 30 years, as part of the EPA’s Lead and Copper Rule, Denver Water has conducted water quality monitoring at homes with known lead service lines and plumbing to determine if the corrosivity of the water supply needs to be adjusted to minimize the risk of lead getting into their household water.

Only once, in 2012, did sample results from those homes indicate that action needed to be taken to optimize corrosion control in the water system, and Denver Water remains in compliance today. However, Denver Water is still required to implement the best method to reduce the risk of lead in tap water for homes with lead plumbing and service lines.

Denver Water conducted a study on multiple treatment options to reduce the potential for lead entering drinking water from lead service lines and household plumbing. Based on the results, Colorado Department of Public Health and Environment, the state regulatory agency that oversees drinking water regulations, required Denver Water to begin adding orthophosphate in March 2020 in accordance with regulatory requirements. The Lead Reduction Program Plan is a proposed alternative to this mandate.

Additional resources:

  • Denver Water has a map of estimated customer-owned lead service lines as a starting point to help customers identify the likelihood of their home having a lead service line. Customers should help verify the accuracy of the information represented by this map by requesting a free water quality test from Denver Water.
  • As part of the education and outreach portion of the plan, Denver Water team members have been at a variety of events this summer and will continue to do so in the future. Community members can visit the project website for an updated calendar of activities.
  • If you suspect your home has lead in the piping, there are a few immediate steps you can take to minimize exposure:
    • Use a filter certified for lead removal for drinking and cooking.
    • Use only cold water for drinking, cooking and making baby formula. Remember, boiling water does not remove lead from water and hot water often contains higher levels of lead than cold water.
    • If water has not been used in the home for a few hours, such as first thing in the morning or when getting home from work, run the kitchen or any bathroom faucet for 5 minutes (remember to capture the water and reuse it!). You also can run the dishwasher, take a shower or do a load of laundry to help flush water in your internal plumbing before drinking or cooking.
    • Replace the filter cartridge according to the manufacturer’s instructions.
    • Regularly clean your faucet’s screen (also known as an aerator). View step-by-step instructions.


Denver Water proudly serves high-quality water and promotes its efficient use to 1.5 million people in the city of Denver and many surrounding suburbs. Established in 1918, the utility is a public agency funded by water rates, new tap fees and the sale of hydropower, not taxes. It is Colorado’s oldest and largest water utility. Subscribe to TAP to hydrate your mind, and follow us on Facebook, Twitter and Instagram.