# Centennial, CO — Drinking Water Quality (2023)

> Contaminant levels for the Centennial, CO public water system from its 2023 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/co/centennial/2023
- JSON API: https://www.thewatermap.com/api/water/co/centennial/2023
- Source: the utility's annual Consumer Confidence Report (CCR)
- Verification: transcribed by a model, cross-checked by a second model, approved before publishing
- Reporting year: 2023
- Contaminants measured: 30
- Contaminants with a federal limit: 22
- Contaminants at or above the federal limit: 8
- Part of The Water Map — https://www.thewatermap.com

## Contaminants measured

| Contaminant | Category | Measured level | Sampling context | Federal limit | Status |
|---|---|---|---|---|---|
| Chloramine | Disinfectants | 2023 (Reported level) | Time Period | 4 (MRDL) | At or above the limit |
| Chlorine | Disinfectants | 1.71–0.2 mg/L (Average) | System-wide | 4 mg/L (MRDL) | Within the limit |
| Chlorite | Disinfection byproducts | 0.47 mg/L (Average) | System-wide | 1 mg/L (MCL) | Within the limit |
| HAA5 | Disinfection byproducts | 21.9 ug/L (Running annual avg) | Locational RAA | 60 ug/L (MCL) | Within the limit |
| TTHM | Disinfection byproducts | 38.5 ug/L (Running annual avg) | Locational RAA | 80 ug/L (MCL) | Within the limit |
| Fluoride | Inorganic chemicals | 618 ug/L (Average) | System-wide | 4 ug/L (MCL) | At or above the limit |
| Nitrate | Inorganic chemicals | 91 ug/L (Average) | System-wide | 10 ug/L (MCL) | At or above the limit |
| Arsenic | Metals | 1.3 ug/L (Average) | System-wide | 10 ug/L (MCL) | Within the limit |
| Barium | Metals | 41.3 ug/L (Average) | System-wide | 2 ug/L (MCL) | At or above the limit |
| Chromium, Total | Metals | 0.91 ug/L (Average) | System-wide | 100 ug/L (MCL) | Within the limit |
| Copper | Metals | 60 ug/L (90th percentile) | At the tap | 1 ug/L (Action level) | At or above the limit |
| Lead | Metals | 3.9 ug/L (90th percentile) | At the tap | 15 ug/L (Action level) | Within the limit |
| Lithium | Metals | 9.23 ug/L (Average) | Treatment plant | 9 ug/L (MCL) | At or above the limit |
| Nickel | Metals | 0.94 ug/L (Average) | System-wide | No federal limit | Detected — no federal limit |
| Selenium | Metals | 4.33 ug/L (Average) | System-wide | 50 ug/L (MCL) | Within the limit |
| Sodium | Metals | 24000 ug/L (Average) | System-wide | No federal limit | Detected — no federal limit |
| Total Coliform | Microbial | 2 (Reported level) | Number of Positives | 0 (MCLG) | Detected — no federal limit |
| Perfluorobutanesulfonic acid | PFAS ("forever chemicals") | 4.64 ng/L (Average) | System-wide | No federal limit | Detected — no federal limit |
| Perfluorohexanesulfonic acid | PFAS ("forever chemicals") | 1.72 ng/L (Average) | System-wide | No federal limit | Detected — no federal limit |
| Perfluorohexanoic acid | PFAS ("forever chemicals") | 0.56 ng/L (Average) | System-wide | No federal limit | Detected — no federal limit |
| Perfluoropentanoic acid | PFAS ("forever chemicals") | 0.72 ng/L (Average) | System-wide | No federal limit | Detected — no federal limit |
| PFBA | PFAS ("forever chemicals") | 0.78 ng/L (Average) | System-wide | No federal limit | Detected — no federal limit |
| PFOA | PFAS ("forever chemicals") | 4.09 ng/L (Average) | System-wide | 4 ng/L (MCL) | At or above the limit |
| PFOS | PFAS ("forever chemicals") | 3.02 ng/L (Average) | System-wide | 4 ng/L (MCL) | Within the limit |
| TOC | Physical & aggregate | 2.31 (Average) | System-wide | 1 (Treatment technique) | At or above the limit |
| Turbidity | Physical & aggregate | 0.203 NTU (Reported level) | System-wide | No federal limit | Detected — no federal limit |
| Combined Radium | Radionuclides | 1.85 pCi/L (Average) | System-wide | 5 pCi/L (MCL) | Within the limit |
| Gross Alpha | Radionuclides | 3.63 pCi/L (Average) | System-wide | 15 pCi/L (MCL) | Within the limit |
| Gross Beta Particle Activity | Radionuclides | 5.6 pCi/L (Average) | System-wide | 50 pCi/L (MCL) | Within the limit |
| Uranium | Radionuclides | 2.39 ug/L (Average) | System-wide | 30 ug/L (MCL) | Within the limit |

## What these contaminants are

- **Chloramine** — A longer-lasting disinfectant made by combining chlorine with ammonia. Holds disinfection further into the pipe network, but is regulated under the same residual-disinfectant cap as chlorine.
- **Chlorine** — A disinfectant added to drinking water to kill bacteria and viruses. Effective and necessary, but high residual levels can cause taste and odor issues; the EPA caps the residual disinfectant level.
- **HAA5** — Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. Long-term exposure above the federal limit is associated with an increased cancer risk.
- **TTHM** — Total trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. Long-term exposure above the federal limit is linked to liver, kidney, and central-nervous-system effects and increased cancer risk.
- **Fluoride** — A mineral often added to drinking water to help prevent tooth decay. Beneficial at low levels, but long-term exposure above the federal limit can cause bone disease and tooth mottling.
- **Nitrate** — A compound from fertilizer runoff, septic systems, and erosion of natural deposits. Levels above the federal limit can cause 'blue baby syndrome,' a serious oxygen-transport condition in infants.
- **Arsenic** — A naturally occurring element that also enters water from industry and agriculture. A known human carcinogen; long-term exposure is linked to skin, bladder, and lung cancer.
- **Barium** — A metal from erosion of natural deposits and industrial discharge. Long-term exposure above the federal limit can raise blood pressure.
- **Chromium, Total** — Total chromium — the sum of all chromium forms, from natural deposits and industrial discharge. Long-term exposure above the federal limit can cause allergic dermatitis; includes hexavalent chromium.
- **Copper** — A metal that enters water from corroding household plumbing. Short-term exposure causes stomach distress; long-term exposure can damage the liver and kidneys.
- **Lead** — A toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. There is no safe level of lead; it harms brain development in children and raises blood pressure in adults. The EPA sets an action level, not a health goal above zero.
- **Lithium** — A naturally occurring element found in some groundwater. No enforceable federal limit; on the EPA contaminant candidate list for further study.
- **Nickel** — A metal from natural deposits and industrial discharge. Long-term exposure can cause skin and other effects; monitored under EPA rules.
- **Selenium** — A trace element from natural deposits and industrial discharge. Essential in tiny amounts, but long-term exposure above the federal limit can cause hair and fingernail loss and circulatory problems.
- **Sodium** — A naturally occurring salt component. Not federally regulated for health; relevant for people on sodium-restricted diets.
- **Total Coliform** — A group of bacteria used as an indicator of overall water-system sanitation. Coliforms themselves are usually harmless, but their presence signals that disease-causing organisms could enter the system.
- **Perfluorobutanesulfonic acid** — Perfluorobutanesulfonic acid, a shorter-chain PFAS 'forever chemical.' Has no standalone limit but is part of the EPA PFAS Hazard Index that limits PFAS in combination.
- **Perfluorohexanesulfonic acid** — Perfluorohexanesulfonic acid, a PFAS 'forever chemical.' Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
- **Perfluorohexanoic acid** — Perfluorohexanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and widely detected.
- **Perfluoropentanoic acid** — Perfluoropentanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
- **PFBA** — Perfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment and the human body.
- **PFOA** — Perfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. Linked to cancer, liver damage, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
- **PFOS** — Perfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. Linked to cancer, thyroid disease, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
- **TOC** — Total organic carbon — a measure of organic material dissolved in the water. Not harmful itself, but it is the raw material that forms disinfection byproducts; removal is a treatment requirement.
- **Turbidity** — A measure of cloudiness from suspended particles in the water. High turbidity can shelter microbes from disinfection; the EPA enforces it through a treatment-technique standard.
- **Combined Radium** — Combined radium-226 and radium-228 — naturally occurring radioactive elements. Long-term exposure above the federal limit increases the risk of bone cancer.
- **Gross Alpha** — Gross alpha particle activity — a combined measure of alpha-emitting radioactive substances. Long-term exposure above the federal limit increases cancer risk.
- **Gross Beta Particle Activity** — Gross beta particle activity — a combined measure of beta-emitting radioactive substances. Long-term exposure above the federal screening level increases cancer risk.
- **Uranium** — A naturally occurring radioactive metal from erosion of natural deposits. Long-term exposure above the federal limit can damage the kidneys and increase cancer risk.

## How to read this

- A water-quality report covers an entire service area, not a single address.
- 'Federal limit' is the EPA standard (MCL, action level, treatment technique, etc.) that the measured level is compared against.
- 'At or above the federal limit' means the utility's own reported figure met or exceeded that standard.

_Figures are the utility's own published numbers. Generated 2026-05-25 from thewatermap.com._