01The verdict: is Seaside water safe?
Seaside's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (87.2/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 2 water systems serve approximately 3,150 residents using groundwater (wells).
1 unresolved violation on record
EPA records show an open compliance item for this system. Most are administrative, but unresolved items are worth watching.
See what was cited ↓Top half in California
Seaside ranks #214 of 690 graded California cities.
See the comparison ↓A flood-prone service area
10 federal disaster declarations on record. After severe weather, watch for boil-water advisories.
See the risk factors ↓Seaside's drinking water received a grade of A- (87.2 out of 100), indicating good water quality. The city's 2 water systems serve approximately 3,150 residents using groundwater.
Lead levels were measured at 10.0 ppb (90th percentile), which is within EPA limits but above recommended levels. This system has not yet been tested for PFAS under the EPA UCMR 5 program. The system has 13 violations on record, including 1 health-based violation. 1 remains unresolved.
Seaside ranks #214 out of 690 cities in California for water quality, placing it mid-range in the state. Seaside relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff. While lead levels are within EPA limits, they are above the recommended 5 ppb threshold that health organizations consider ideal. A point-of-use filter adds an extra layer of protection. As a small community water system, Seaside may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Seaside's water
Every contaminant flagged in Seaside, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 10.0 | 15 | ppb | Inorganic | Safe |
Cities ranked by 90th-percentile lead PF PFAS in California
Cities ranked by compounds detected Cu Copper in California
Cities ranked by 90th-percentile copper
03Seaside's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 13 violations on record, including 1 health-based violation. 1 remains unresolved.
All ten of the last ten years were clean — no EPA violations recorded for Seaside.
▲ Up 10 ppb since 1997. Latest reading: 10 ppb (2024) — 67% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Seaside's water comes from
Seaside's drinking water is drawn from underground aquifers through wells.
Groundwater
Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.
Local treatment
Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.
2 systems
2 water systems, operated under local government ownership.
3,150 people
Residents served across Seaside's service area.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals. Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds. The system is operated by local government ownership and serves approximately 3,150 people through 2 water systems.
| System name | PWSID | Population | Source |
|---|---|---|---|
| SEASIDE MUNICIPAL WATER SYSTEM | CA2710018 | 2,800 | Groundwater |
| SUNSET WEST COMMUNITY LLC | CA1000378 | 350 | Groundwater |
Water bodies near Seaside
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Seaside's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Industrial discharge
2 facilities within 10 miles reported 0 lb released to surface water in the latest EPA Toxics Release Inventory. Proximity doesn't equal tap contamination — treatment and hydrology decide — but it's pressure on the watershed.
Flood & storm history
10 federal disaster declarations on record for Monterey County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Superfund proximity
1 National Priorities List site within 10 miles. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
06How Seaside compares
Scores for nearby California cities on one line, with the average marked.
dashed line = California average (57/100)
Seaside scores 87.2/100 — above the California average of 57/100. It outscores 8 of 10 nearby cities. Full California rankings →
42.8 / 100FSan Jose, CA
28 / 100BOakland, CA
77.9 / 100FSan Diego, CA
39.7 / 100FSacramento, CA
31.2 / 100ABurlingame, CA
89.2 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
07What to do at home
Steps matched to what testing actually found in Seaside's water — not generic advice.
Filter drinking & cooking water
Basic carbon filter for extra protection. Lead detected at 10.0 ppb
Compare tested filters →Flush taps & check your service line
Lead leaches from pipes as water sits. Run cold water 30 seconds before drinking (especially mornings), and ask the utility whether your address still has a lead service line.
Lead risks explained →Watch for Seaside alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is Seaside, CA tap water safe to drink?
Seaside's water quality earned a grade of A- (87.2/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #214 out of 690 cities tested in California.
What contaminants are in Seaside's water?
Lead was measured at 10.0 ppb (90th percentile). 13 violations are on record.
How is Seaside's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Seaside?
While lead levels are within EPA limits, a filter adds extra protection. Based on current data, basic filtration should suffice for additional peace of mind.
Where does Seaside's water come from?
Seaside's water is sourced from Groundwater. The city has 2 water systems serving approximately 3,150 residents.
What health violations has Seaside's water system had?
Seaside has 1 health-based violation on record. The most recent violation was recorded in August 2009. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.
Is Seaside's groundwater at risk of contamination?
Seaside uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 13 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Seaside's water compare to other cities?
Seaside ranks #214 out of 690 cities in California (better than 69% of state cities) and #4172 out of 15382 cities nationally (73th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.