Water Quality Report · Updated October 07, 2026
MOULTON NIGUEL WATER DISTRICT
MOULTON NIGUEL WATER DISTRICT delivers tap water graded B (76/100) by TapWaterSafety.org. The utility serves approximately 170,236 residents in LAGUNA HILLS, California using surface water (purchased). The most significant water quality concerns are: Haloacetic acids (HAA5) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Haloacetic acids (HAA9) significantly above health guideline. For questions, the utility can be reached at 949-448-4032.
Is LAGUNA HILLS tap water safe to drink?
MOULTON NIGUEL WATER DISTRICT delivers tap water that earns a grade of B (76/100) from TapWaterSafety.org — a good rating, with only minor concerns relative to health-based guidelines.
The utility serves 170,236 residents in LAGUNA HILLS, drawing from surface water (purchased).
Public testing data identifies 11 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA5), Total trihalomethanes (TTHMs), Haloacetic acids (HAA9), Bromodichloromethane, Dibromochloromethane, Dibromoacetic acid, Trichloroacetic acid, Dichloroacetic acid, Chloroform, Bromoform, Chromium (hexavalent). For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
EPA compliance record
Official U.S. EPA records for MOULTON NIGUEL WATER DISTRICT (system ID CA3010073) for the last 3 years. Checked 2026-10-07.
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Quick actions for LAGUNA HILLS residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for MOULTON NIGUEL WATER DISTRICT.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 36.2 ppb, 362x above the EWG health guideline of 0.1 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 39.0 ppb, 260x above the EWG health guideline of 0.15 ppb.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 13.6 ppb, 227x above the EWG health guideline of 0.06 ppb.
Contact MOULTON NIGUEL WATER DISTRICT
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Recommended water filters for LAGUNA HILLS
Filters matched to the specific contaminants in this water supply.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 76/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA5) Disinfection byproduct |
36.2 ppb | 0.1 | 60.0 | 60 | — | — | — | 362× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
39.0 ppb | 0.15 | 80.0 | 100 | — | — | — | 260× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
13.6 ppb | 0.06 | — | — | — | — | — | 227× over |
| Bromodichloromethane Disinfection byproduct |
11.6 ppb | 0.06 | — | — | — | — | — | 194× over |
| Dibromochloromethane Disinfection byproduct |
11.1 ppb | 0.1 | — | — | — | — | — | 111× over |
| Dibromoacetic acid Disinfection byproduct |
2.64 ppb | 0.03 | — | — | — | — | — | 88× over |
| Trichloroacetic acid Disinfection byproduct |
4.99 ppb | 0.1 | — | — | — | — | — | 50× over |
| Dichloroacetic acid Disinfection byproduct |
7.47 ppb | 0.2 | — | — | — | — | — | 37× over |
| Chloroform Disinfection byproduct |
13.4 ppb | 0.4 | — | — | — | — | — | 33× over |
| Bromoform Disinfection byproduct |
3.02 ppb | 0.5 | — | — | — | — | — | 6.0× over |
| Chromium (hexavalent) Heavy metal |
0.0749 ppb | 0.02 | — | — | — | — | — | 3.7× over |
| Chlorate Disinfection byproduct |
116.1 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
3.18 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
4.41 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
4.06 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Strontium Radiological |
0.864 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Lithium Other |
33.8 ppb | — | — | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
MOULTON NIGUEL WATER DISTRICT service area
This water system serves 1 community in Orange County, California. Click any city for its dedicated tap water quality page.
Find the right filter for LAGUNA HILLS water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.