91941
La Mesa, CA
San Diego County · San Diego-Chula Vista-Carlsbad, CA metro area
HELIX WATER DISTRICT
Is tap water in Casa de Oro-Mount Helix (91941) safe to drink?
Source: Official EPA UCMR5 federal monitoring data. Last tested October 2024.
Township:
- San Diego CCD, CA
Neighborhoods:
- Cajon Heights
- Montezuma Mesa
- Aztec Center
- Mid-City:Eastern Area
- College Area
- Lomita
The short answer for Casa de Oro-Mount Helix (91941)
La Mesa tap water has 7 contaminants above EPA guidelines, including lithium at 3.3× the limit (tested October 2023). See the full compound-by-compound breakdown and filter recommendations.
The health risk for La Mesa
lithium has been detected above EPA limits in this water system's recent tests. A certified filter designed for this contaminant type is strongly recommended.
- lithium above limit.
lithium concentration (µg/L)
October 2023
0 µg/L
10 µg/L
50 µg/L
33.000 µg/L
Detected
µg/L
10 µg/L
EPA limit
guideline
230% above limit
Comparison
vs. guideline
EPA limit: 10 µg/L | Your water: 33.000 µg/L
Certified Filters for La Mesa Tap Water
lithium was detected above EPA limits. These filters are independently certified to reduce common drinking-water contaminants.
Pitcher filter
Epic Pure XP Water Filter Pitcher
NSF-certified dual-layer filtration reduces 70+ contaminants including PFAS, lead, chlorine, microplastics, and bacteria.
NSF/ANSI 42, 53, 401 & P473Removes 99.99% PFASMade in USABPA-free
PFAS detected in 91941 · What you can do
Here's what actually removes PFAS from your water
The right filter eliminates PFAS at the tap. But not all filters do - and the type you choose matters for your home.
Common pitchers like Brita do not remove PFAS. You need a filter independently certified to NSF P473 (for pitcher filters) or NSF/ANSI 58 (for reverse osmosis systems). All three options below carry the relevant certification.
Certified PFAS filter types - how they differ
Certified Pitcher
Removes PFAS (99%+)
No installation, works today
Lowest upfront cost (~$70)
Must refill manually
Filters only what you pour in - not cooking water
Reverse Osmosis More complete
Removes PFAS + lead, arsenic, nitrates & more
Always-on - no refilling ever
Noticeably better tasting water
Filters drinking & cooking water automatically
Higher upfront cost ($200-$400)
Choose your option
Most elevated compounds
| Compound | Measurement | EPA Limit | Comparison |
|---|---|---|---|
| lithium Tested: October 2023 · Miramar WTP |
33.000 µg/L | 10 µg/L | 230% above limit |
| lithium Tested: October 2023 · Alvarado WTP |
32.000 µg/L | 10 µg/L | 220% above limit |
| lithium Tested: April 2024 · Helix Intertie |
28.900 µg/L | 10 µg/L | 189% above limit |
| lithium Tested: October 2024 · Levy Filtration Plant |
25.000 µg/L | 10 µg/L | 150% above limit |
| lithium Tested: October 2023 · Otay WTP |
25.000 µg/L | 10 µg/L | 150% above limit |
View all tested compounds
Alvarado WTP · Tested: Multiple dates
| Compound | Measurement | EPA Limit | Comparison |
|---|---|---|---|
| lithium | 32.000 µg/L | 10 µg/L | 220% above limit |
| PFHxS | <0.003 µg/L | 0.004 µg/L | Below limit |
| HFPO-DA | <0.005 µg/L | 0.01 µg/L | Below limit |
| PFNA | <0.004 µg/L | 0.01 µg/L | Below limit |
| PFHxA | <0.003 µg/L | 3 µg/L | Below limit |
| PFBA | <0.005 µg/L | 6 µg/L | Below limit |
| 11Cl-PF3OUdS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 4:2 FTS | <0.003 µg/L | 0.003 µg/L | Below limit |
| 6:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 8:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 9Cl-PF3ONS | <0.002 µg/L | 0.002 µg/L | Below limit |
| ADONA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFBS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDoA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFOA | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFOS | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFPeA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFTrDA | <0.007 µg/L | 0.007 µg/L | Below limit |
| PFUnA | <0.002 µg/L | 0.002 µg/L | Below limit |
Helix Intertie · Tested: April 2024
| Compound | Measurement | EPA Limit | Comparison |
|---|---|---|---|
| lithium | 28.900 µg/L | 10 µg/L | 189% above limit |
| PFHxS | <0.003 µg/L | 0.004 µg/L | Below limit |
| HFPO-DA | <0.005 µg/L | 0.01 µg/L | Below limit |
| PFNA | <0.004 µg/L | 0.01 µg/L | Below limit |
| PFHxA | <0.003 µg/L | 3 µg/L | Below limit |
| PFBA | <0.005 µg/L | 6 µg/L | Below limit |
| 11Cl-PF3OUdS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 4:2 FTS | <0.003 µg/L | 0.003 µg/L | Below limit |
| 6:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 8:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 9Cl-PF3ONS | <0.002 µg/L | 0.002 µg/L | Below limit |
| ADONA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFBS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDoA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFOA | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFOS | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFPeA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFTrDA | <0.007 µg/L | 0.007 µg/L | Below limit |
| PFUnA | <0.002 µg/L | 0.002 µg/L | Below limit |
Levy Filtration Plant · Tested: October 2024
| Compound | Measurement | EPA Limit | Comparison |
|---|---|---|---|
| lithium | 25.000 µg/L | 10 µg/L | 150% above limit |
| PFHxS | <0.003 µg/L | 0.004 µg/L | Below limit |
| HFPO-DA | <0.005 µg/L | 0.01 µg/L | Below limit |
| PFNA | <0.004 µg/L | 0.01 µg/L | Below limit |
| PFHxA | <0.003 µg/L | 3 µg/L | Below limit |
| PFBA | <0.005 µg/L | 6 µg/L | Below limit |
| 11Cl-PF3OUdS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 4:2 FTS | <0.003 µg/L | 0.003 µg/L | Below limit |
| 6:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 8:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 9Cl-PF3ONS | <0.002 µg/L | 0.002 µg/L | Below limit |
| ADONA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFBS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDoA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFOA | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFOS | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFPeA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFTrDA | <0.007 µg/L | 0.007 µg/L | Below limit |
| PFUnA | <0.002 µg/L | 0.002 µg/L | Below limit |
Miramar WTP · Tested: Multiple dates
| Compound | Measurement | EPA Limit | Comparison |
|---|---|---|---|
| lithium | 33.000 µg/L | 10 µg/L | 230% above limit |
| PFHxS | <0.003 µg/L | 0.004 µg/L | Below limit |
| HFPO-DA | <0.005 µg/L | 0.01 µg/L | Below limit |
| PFNA | <0.004 µg/L | 0.01 µg/L | Below limit |
| PFHxA | <0.003 µg/L | 3 µg/L | Below limit |
| PFBA | <0.005 µg/L | 6 µg/L | Below limit |
| 11Cl-PF3OUdS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 4:2 FTS | <0.003 µg/L | 0.003 µg/L | Below limit |
| 6:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 8:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 9Cl-PF3ONS | <0.002 µg/L | 0.002 µg/L | Below limit |
| ADONA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFBS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDoA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFOA | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFOS | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFPeA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFTrDA | <0.007 µg/L | 0.007 µg/L | Below limit |
| PFUnA | <0.002 µg/L | 0.002 µg/L | Below limit |
Otay WTP · Tested: Multiple dates
| Compound | Measurement | EPA Limit | Comparison |
|---|---|---|---|
| lithium | 25.000 µg/L | 10 µg/L | 150% above limit |
| PFHxS | <0.003 µg/L | 0.004 µg/L | Below limit |
| HFPO-DA | <0.005 µg/L | 0.01 µg/L | Below limit |
| PFNA | <0.004 µg/L | 0.01 µg/L | Below limit |
| PFHxA | <0.003 µg/L | 3 µg/L | Below limit |
| PFBA | <0.005 µg/L | 6 µg/L | Below limit |
| 11Cl-PF3OUdS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 4:2 FTS | <0.003 µg/L | 0.003 µg/L | Below limit |
| 6:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 8:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 9Cl-PF3ONS | <0.002 µg/L | 0.002 µg/L | Below limit |
| ADONA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFBS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDoA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFOA | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFOS | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFPeA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFTrDA | <0.007 µg/L | 0.007 µg/L | Below limit |
| PFUnA | <0.002 µg/L | 0.002 µg/L | Below limit |
Purchased water representative sample site · Tested: Multiple dates
| Compound | Measurement | EPA Limit | Comparison |
|---|---|---|---|
| lithium | 16.000 µg/L | 10 µg/L | 60% above limit |
| PFHxS | <0.003 µg/L | 0.004 µg/L | Below limit |
| HFPO-DA | <0.005 µg/L | 0.01 µg/L | Below limit |
| PFNA | <0.004 µg/L | 0.01 µg/L | Below limit |
| PFHxA | <0.003 µg/L | 3 µg/L | Below limit |
| PFBA | <0.005 µg/L | 6 µg/L | Below limit |
| 11Cl-PF3OUdS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 4:2 FTS | <0.003 µg/L | 0.003 µg/L | Below limit |
| 6:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 8:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 9Cl-PF3ONS | <0.002 µg/L | 0.002 µg/L | Below limit |
| ADONA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFBS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDoA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFOA | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFOS | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFPeA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFTrDA | <0.007 µg/L | 0.007 µg/L | Below limit |
| PFUnA | <0.002 µg/L | 0.002 µg/L | Below limit |
SDCWA Intertie · Tested: April 2024
| Compound | Measurement | EPA Limit | Comparison |
|---|---|---|---|
| lithium | 16.200 µg/L | 10 µg/L | 62% above limit |
| PFHxS | <0.003 µg/L | 0.004 µg/L | Below limit |
| HFPO-DA | <0.005 µg/L | 0.01 µg/L | Below limit |
| PFNA | <0.004 µg/L | 0.01 µg/L | Below limit |
| PFHxA | <0.003 µg/L | 3 µg/L | Below limit |
| PFBA | <0.005 µg/L | 6 µg/L | Below limit |
| 11Cl-PF3OUdS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 4:2 FTS | <0.003 µg/L | 0.003 µg/L | Below limit |
| 6:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 8:2 FTS | <0.005 µg/L | 0.005 µg/L | Below limit |
| 9Cl-PF3ONS | <0.002 µg/L | 0.002 µg/L | Below limit |
| ADONA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFBS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFDoA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFHpS | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFOA | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFOS | <0.004 µg/L | 0.004 µg/L | Below limit |
| PFPeA | <0.003 µg/L | 0.003 µg/L | Below limit |
| PFTrDA | <0.007 µg/L | 0.007 µg/L | Below limit |
| PFUnA | <0.002 µg/L | 0.002 µg/L | Below limit |
Water utilities serving ZIP 91941
Service area boundaries are approximate and based on state filings or modeled estimates. Contact your utility to confirm exact service at a specific address.
- HELIX WATER DISTRICTAction advised
Modeled boundaries are shown with a dashed outline.
Frequently Asked Questions about ZIP 91941 Tap Water
What contaminants are above EPA limits in ZIP 91941?
ZIP 91941 has 7 contaminants above EPA health guidelines in the latest available data, including lithium at 3.3x the EPA guideline. The full table on this page lists every tested compound and its measured level.
Will boiling ZIP 91941 tap water remove lithium?
No. Boiling tap water does not remove lithium. Lithium is a dissolved mineral, so heat does not break it down and evaporation can actually concentrate it. Reverse osmosis (NSF/ANSI 58) is the most reliable at-home option for reducing lithium.
Do basic pitcher filters remove lithium?
Standard pitcher filters are not certified to reduce lithium. Reverse osmosis (NSF/ANSI 58) is the most widely available home option for reducing lithium in drinking water.
Who provides tap water in ZIP 91941?
Public records identify HELIX WATER DISTRICT as a primary water system associated with ZIP 91941. Service boundaries can vary by address, so confirm exact service with the utility.
When was ZIP 91941 tap water last tested?
The most recent test date used in this report is October 2024. EnviroClarity last refreshed this page on 2026-05-04.
Where can I find the official water quality report for ZIP 91941?
Every U.S. public water system is required to publish an annual Consumer Confidence Report (CCR). Contact HELIX WATER DISTRICT or visit their website for the latest official report covering ZIP 91941. The EPA also maintains a national CCR locator.
Check another ZIP code
Nearby ZIP reports
- 91942 - Navajo, La Mesa tap water report
- 91945 - Lemon Grove tap water report
- 91977 - La Presa tap water report
- 92119 - Greenbrier Mobile Home Park, San Diego tap water report
- 92020 - El Cajon tap water report
- 92115 - Montezuma Mesa, San Diego tap water report
- 91978 - Spring Valley tap water report
- 92182 - College Area, San Diego tap water report
Data reflects publicly reported utility records from EPA datasets and local utility disclosures. This information is educational and not medical advice.