City of Longmont

Longmont's municipal water comes entirely from surface sources including streams, ponds and reservoirs fed by snowmelt and rainfall. The primary water sources include:

The St. Vrain Creek watershed, which encompasses both North and South St. Vrain Creeks. The North St. Vrain watershed includes pristine wilderness areas and portions of the Rugged Mountain National Recreation area, with Ralph Price Reservoir storing water from this source. The South St. Vrain watershed extends into the Indian Peaks Wilderness, with both branches merging near Lyons to form St. Vrain Creek.

During the reporting year, approximately 38% of Longmont's water originated from the North St. Vrain and St. Vrain Creeks. Water from lower St. Vrain Creek (below Lyons) is transported to Burch Lake via the Palmerton Ditch, though Burch Lake wasn't utilized during this reporting period.

Additional water comes from the Colorado and Fraser Rivers in Grand County, delivered through the Colorado-Big Thompson (C-BT) project managed by the Northern Colorado Water Conservancy District.

WHAT'S IN THE WATER BEFORE TREATMENT?

Municipal water sources (both tap and bottled) may contain various contaminants, including:

• Microbial contaminants (viruses and bacteria) from sewage treatment plants, septic systems, agricultural operations, and wildlife
• Inorganic contaminants (salts and metals) from natural sources, urban runoff, industrial wastewater, oil/gas production, and farming
• Pesticides and herbicides from agriculture, urban runoff, and residential use
• Organic chemical contaminants from industrial processes, petroleum production, gas stations, and septic systems
• Radioactive contaminants from natural sources or from oil/gas production and mining

Longmont is fortunate to have high-quality source waters that originate in mountain watersheds. The North St. Vrain watershed is primarily wilderness affected only by natural elements. The South St. Vrain may be impacted by abandoned mine runoff. The C-BT project watersheds may contain contaminants related to recreation, wastewater treatment, and pasture runoff. St. Vrain Creek below Lyons is conveyed via irrigation ditches and may be affected by agricultural activities.

To ensure safe drinking water, the EPA establishes regulations limiting contaminant levels in public water systems. Longmont's treatment facilities reduce contaminants to levels that meet or exceed Federal and State requirements.

The Colorado Department of Public Health and Environment (CDPHE) has completed a Source Water Assessment Report for Longmont. For a copy, call 303-651-8416 or visit the SWAP website at colorado.gov/cdphe/source-water-assessment-and-protection-swap.

The City monitors water quality throughout the watershed, collecting samples from reservoirs, creeks, and the storm drainage system. This information helps optimize treatment plant operations to maintain high water quality standards.

BOTTLED WATER CONSIDERATIONS

FDA regulations establish contaminant limits for bottled water similar to EPA standards for tap water. However, testing requirements for bottled water are significantly less stringent than for municipal supplies. All drinking water, including bottled varieties, contains at least trace amounts of some contaminants. For more information about bottled water safety, contact the EPA's Safe Drinking Water Hotline (1-800-426-4791) or the Natural Resources Defense Council, which has tested many bottled water brands (nrdc.org/stories/truth-about-tap).

HEALTH CONSIDERATIONS

Some individuals may be particularly vulnerable to contaminants in drinking water. Immunocompromised persons, including those undergoing chemotherapy, organ transplant recipients, people with HIV/AIDS, elderly individuals, and infants may face increased infection risks. These individuals should consult healthcare providers about appropriate precautions. EPA/CDC guidelines on reducing Cryptosporidium infection risk are available from the Safe Drinking Water Hotline (1-800-426-4791).

LEAD AWARENESS

Elevated lead levels can cause serious health problems, especially for pregnant women and young children. Lead in water primarily comes from materials in service lines and home plumbing. While Longmont provides high-quality water, they cannot control the variety of materials used in plumbing components. If your water has been sitting for several hours, minimize lead exposure by flushing your tap for 30 seconds to 2 minutes before using water for drinking or cooking. If concerned, consider having your water tested. Information about lead in drinking water is available from the Safe Drinking Water Hotline or at epa.gov/safewater/lead.

The City's State-certified Water Quality Laboratory performs most water quality tests, with specialized testing outsourced to contract laboratories. Last year, 12,206 tests were performed on Longmont's water, with 9,186 conducted by the City's own laboratory, ensuring that water delivered to residents meets the highest quality standards.

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