# Vallecitos Wd — San Marcos, Ca, CA — Drinking Water Quality (2023)

> Contaminant levels for the Vallecitos Wd — San Marcos, Ca, CA public water system from its 2023 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ca/vallecitos-wd-san-marcos-ca/2023
- JSON API: https://www.thewatermap.com/api/water/ca/vallecitos-wd-san-marcos-ca/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: 23
- Contaminants with a federal limit: 8
- Contaminants at or above the federal limit: 1
- Part of The Water Map — https://www.thewatermap.com

## Contaminants measured

| Contaminant | Category | Measured level | Sampling context | Federal limit | Status |
|---|---|---|---|---|---|
| Bromate | Disinfection byproducts | 0–8.5 ug/L (Reported level) | Twin Oaks Treatment Plant | No federal limit | Approaching the limit |
| HAA5 | Disinfection byproducts | 0–27 ug/L (Reported level) | Within VWD's System | No federal limit | Within the limit |
| Chloride | Inorganic chemicals | 48–110 mg/L (Reported level) | Carlsbad Desalination Plant | No federal limit | Detected — no federal limit |
| Fluoride | Inorganic chemicals | 0.6–0.8 mg/L (Reported level) | Carlsbad Desalination Plant | 4 mg/L (MCL) | Within the limit |
| Nitrate | Inorganic chemicals | Not detected mg/L (Reported level) | Weese Treatment Plant | 10 mg/L (MCL) | None detected |
| Sulfate | Inorganic chemicals | 152–217 mg/L (Reported level) | Twin Oaks Treatment Plant | No federal limit | Detected — no federal limit |
| Aluminum | Metals | 0–160 ug/L (Reported level) | Twin Oaks Treatment Plant | No federal limit | Detected — no federal limit |
| Arsenic | Metals | 2.2 ug/L (Reported level) | Olivenhain Treatment Plant | No federal limit | Within the limit |
| Barium | Metals | 0.095–0.122 mg/L (Reported level) | Twin Oaks Treatment Plant | 2 mg/L (MCL) | Within the limit |
| Copper | Metals | 0.25 mg/L (Reported level) | Within VWD's System | 1.3 mg/L (Action level) | Within the limit |
| Lead | Metals | 1.7 ug/L (Reported level) | Within VWD's System | No federal limit | Within the limit |
| Manganese | Metals | Not detected ug/L (Reported level) | Twin Oaks Treatment Plant | No federal limit | None detected |
| Escherichia coli (E. coli) | Microbial | 0 (Reported level) | Carlsbad Desalination Plant | 0 (Public health goal) | None detected |
| Total Coliform | Microbial | 0 % (Reported level) | Skinner Treatment Plant | No federal limit | None detected |
| Chlorine Total | Other | 0.3–3.4 mg/L (Reported level) | Within VWD's System | No federal limit | Approaching the limit |
| Color | Physical & aggregate | 0–3 (Reported level) | Weese Treatment Plant | No federal limit | Detected — no federal limit |
| Odor | Physical & aggregate | 0–3 (Reported level) | Weese Treatment Plant | No federal limit | Detected — no federal limit |
| Specific Conductance | Physical & aggregate | 653–1070 (Reported level) | Weese Treatment Plant | No federal limit | Detected — no federal limit |
| Total Dissolved Solids | Physical & aggregate | 474–614 mg/L (Reported level) | Twin Oaks Treatment Plant | No federal limit | Detected — no federal limit |
| Turbidity | Physical & aggregate | 0.1–1.8 NTU (Reported level) | Weese Treatment Plant | 1 NTU (MCL) | At or above the limit |
| Gross Alpha | Radionuclides | 0–4 pCi/L (Reported level) | Skinner Treatment Plant | 15 pCi/L (MCL) | Within the limit |
| Gross Beta Particle Activity | Radionuclides | 0–5 pCi/L (Reported level) | Skinner Treatment Plant | No federal limit | Detected — no federal limit |
| Uranium | Radionuclides | 0–3 pCi/L (Reported level) | Skinner Treatment Plant | 20 pCi/L (MCL) | Detected — no federal limit |

## What these contaminants are

- **Bromate** — A disinfection byproduct formed when bromide-containing water is treated with ozone. Classified as a probable human carcinogen; the EPA sets a strict maximum contaminant 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.
- **Chloride** — A naturally occurring salt compound. Regulated only as a secondary (cosmetic) standard; high levels cause a salty taste and can corrode pipes.
- **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.
- **Sulfate** — A naturally occurring mineral from rock and soil. No health-based federal limit; high levels can have a laxative effect and a bitter taste.
- **Aluminum** — A common element sometimes used as a treatment coagulant. Regulated only as a secondary (cosmetic) standard; high levels can discolor water.
- **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.
- **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.
- **Manganese** — A naturally occurring metal from soil and rock. No enforceable federal limit; high levels stain fixtures and laundry and can affect taste, with a health advisory for infants.
- **Escherichia coli (E. coli)** — Escherichia coli — bacteria found in the gut of humans and animals. Its presence in drinking water indicates fecal contamination and a real risk of waterborne illness.
- **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.
- **Color** — A measure of visible tint in the water. Regulated only as a secondary (cosmetic) standard.
- **Odor** — A measure of detectable smell in the water. Regulated only as a secondary (cosmetic) standard.
- **Specific Conductance** — A measure of how well water conducts electricity, which tracks dissolved mineral content. Not federally regulated for health; used as a proxy for total dissolved solids.
- **Total Dissolved Solids** — Total dissolved solids — the combined content of all dissolved minerals and salts. Regulated only as a secondary (cosmetic) standard; high levels affect taste and hardness.
- **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.
- **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 2026-06-04 from thewatermap.com._