December 2017: LTWD is hiring for two positions: Office Assistant II and Water Resources/Engineering Technician. See below. Emergencies call: (970) 532-2096

December 2017: LTWD is hiring for two positions: Office Assistant II and Water Resources/Engineering Technician. See below.

Emergencies call: (970) 532-2096

Water Quality FAQs

Is Little Thompson Water District’s tap water safe to drink?

Yes, our water more than meets all regulatory mandates and never has violated any standard. Drinking water is regulated through the Colorado Department of Public Health and Environment and the Environmental Protection Agency.

Where does our water come from?

The District’s raw water (untreated) comes primarily from Carter Lake, a water reservoir of the Northern Water’s Colorado Big Thompson Project or C-BT. C-BT water is collected in western slope reservoirs and transported through the Alva B. Adams Tunnel to Mary’s Lake, Lake Estes, Pinewood and Flatiron Reservoirs and finally pumped to Carter Lake.

Is the water protected from contamination?

Through its participation in the C-BT project, the District also participates in the Big Thompson Watershed Forum.    The Big Thompson Watershed Forum is a group of private citizens and government agencies united with the common goal of protecting the quality of source water throughout the Big Thompson Watershed which includes Carter Lake. The Forum is working in partnership with Colorado State University and Northern Colorado Water Conservancy District (Northern Water) to operate a water quality monitoring network for the watershed. More information may be obtained at

What makes my water smell/taste bad?

Water can pick up tastes and odors from new pipe, from low usage in the treated water system or from natural elements in the source water. Taste and odor events often occur seasonally during blooms of algae or aquatic plants. Although the plant material is removed during treatment, sometimes the odors persist. Tastes and odors in treated water are not harmful, but we do take steps to try and eliminate them.

Why is the water discolored?

The discoloration is usually rust from aging pipes. It is not harmful, but is aesthetically displeasing. Discoloration of the water also can be a result of disturbances in the water line due to using a hydrant improperly, installing new pipe, or shutting off the water to a local area for system maintenance. Home plumbing can also cause discoloration of the water.

Do I need a water filter?

Your tap water is safe to drink without a water filter. If you have an internal problem with your plumbing or your home has a lead service line or plumbing that contains lead, you may want to consider a filter or treatment system

Is bottled water safer than tap water?

Many bottled water companies use tap water as the source. Currently, bottled water is not as heavily regulated or tested as tap water. Instead bottled water is regulated through the Food and Drug Administration and is considered a food product. Additionally, water utilities are required to release information on their water’s quality and bottled water companies are not.

Is there lead in my water, and if so what can I do about it?

Please read the advisory in the 2015 Annual Drinking Water Quality Report posted on this website for more information on Lead in the Drinking Water. If you have questions, please contact our office at (970) 532-2096.

Should I be concerned about radon?

No, the District water comes from surface water such as lakes and streams to produce drinking water. Radon is not found in surface waters.

What chemicals do you put in the water?

Carter Lake Filter Plant adds the following chemicals to the water:

  • Coagulants and polymers which causes particles in the water to stick together for removal by filtration.
  • Chlorine dioxide is added to control algae and taste and odor problems commonly found in raw water.
  • Soda ash and/or sodium hydroxide is added to maintain pH levels.
  • Fluoride is found naturally in our water and is added as needed to meet the recommended guidelines set by the state health department.
  • Poly-orthophosphates are added for corrosion control.
  • Chlorine is added as a protection against viruses, bacteria, and other micro-organisms that might remain after the filtration process.

All chemicals we use in our processes are certified as food grade or meet ANSI/NSF 60 Standards for Drinking Water Additives and they meet AWWA standards.

What is in Little Thompson Water District’s treated water?

All natural waters contain minerals and some chemicals absorbed as it flows over rocks and soils. The EPA has identified more than 80 potential contaminants that when present at levels above established limits (Maximum Contaminant Level or MCL) may be a health threat. For more information, please view the latest Annual Drinking Water Quality Report posted on this website.

Can toxic spills that seep into the ground or groundwater contaminate my drinking water?

It is highly unlikely that toxic spills in the ground or groundwater could contaminate the drinking water since the treated water system is enclosed. Find more information on protection of our source water at the Big Thompson Watershed Forum’s website,

How long can tap water be stored and how should it be stored?

Cold tap water can be stored for about two weeks if kept sealed, away from light and cold or at least cooled, in a clean, amber or foil-covered glass or hard plastic container.

The District asks us to conserve the water, yet I see your crews wasting water by flushing hydrants. Why do you do that?

Even the best water can get stale and taste unpleasant if not used sufficiently or if the pipes contain sediment. Flushing is vital, especially in areas where water usage is low.

Is it okay to drink hot water from the tap?

It is not advisable to drink or use hot water from the tap for consumption or food or beverage preparation. Hot water systems (tanks, boilers) contain metallic parts that corrode over time and contaminate the hot water.

How do I treat the water for my fish?

Always use a dechlorinating agent for chloramine.

How will water hardness affect my detergent, iron or humidifier?

Most customers who call about hardness are inquiring for detergent usage amounts, or for adding tap water to their irons or humidifiers. The units of measurement for most appliances are in grains per gallon, but we measure in milligrams per liter.

Hardness in water is defined as the sum of the calcium and magnesium concentrations (salts), expressed as calcium carbonate. The hardness of the water varies with the amounts of these salts. They originate when subterranean and surface waters absorb minerals, including compounds of calcium and magnesium carbonates, bicarbonates, sulfates and chlorides – giving water its hardness. Hard or soft water are not health concerns, but may result in a mineral taste (hard) or a flat, unpleasant taste (soft).

General guidelines for classification of waters are: 0 to 60 mg/L (milligrams per liter) as calcium carbonate is classified as soft; 61 to 120 mg/L as moderately hard; 121 to 180 mg/L as hard; and more than 180 mg/L as very hard.

The hardness of the District’s water is approximately 21.39 mg/L of Calcium Carbonate (CaCO3). (Value from June 2016)



Latest news


December 21, 2017

Little Thompson Water District seeking qualified applicants for Water Resources/Engineering Technician position.  Bachelor’s degree in civil engineering, water resource management…