Wondering if your Prunedale well water is truly safe to drink? With agriculture, septic systems, and older wells in the mix, nitrates can show up in local groundwater and go unnoticed until you test. If you own a private well, you are the water utility for your home, and a simple plan can protect your family. In this guide, you’ll learn what to test, how to read results, what to do if nitrates are high, and where to find trusted local resources. Let’s dive in.
Why nitrates matter in Prunedale
Private wells in Monterey County are not regulated like public systems, so owners must test and maintain their own water. State programs identify nitrate as a common groundwater contaminant in the region, including the Salinas Valley and nearby communities. Likely sources include fertilizers, manure, and failing or poorly sited septic systems. Get familiar with local guidance on nitrate in drinking water from the State Water Board’s overview of nitrate and private wells.
The health benchmark that public systems follow is 10 mg/L nitrate as nitrogen (also seen as 45 mg/L as nitrate). This level is set to protect infants from methemoglobinemia. Review the federal background on the standard through the EPA’s drinking water rules.
What to test and how often
Core annual tests
- Total coliform and E. coli. Bacteria are the most immediate concern and should be tested at least once per year and after any well service or flooding. See homeowner guidance from wellowner.org.
- Nitrate and nitrite. Test annually, and consider more frequent testing if you have infants, are pregnant, or have a history of elevated results.
Baseline every few years
- Arsenic. Found in some domestic wells in Monterey County; get a baseline and retest every few years. Regional well results are summarized in the State’s GAMA Domestic Well Project.
- Metals and basic chemistry. Lead (if older plumbing), manganese, iron, pH, and total dissolved solids help assess health, plumbing impacts, and treatment needs.
Site specific contaminants
- Consider testing for hexavalent chromium, uranium, pesticides, VOCs, and 1,2,3-TCP based on location and land use. Check the State’s GAMA resources for regional context and sampling priorities at the GAMA Domestic Well Project.
How to test in Monterey County
Use certified laboratories
Work with a California ELAP certified drinking water lab for accurate, defensible results. The State Water Board and local programs can help you find labs and guidance on next steps. For regional contacts and updates, see the Central Coast Regional Board’s Groundwater Assessment & Protection.
Cost, timing, and sampling tips
- A basic nitrate plus coliform screening typically runs about $100 to $200. Broader panels with metals and organics can cost several hundred dollars or more, depending on your list. See local cost examples from a Salinas provider at Alvarez Plumbing’s well test overview.
- Follow the lab’s instructions closely. Many bacterial samples must be analyzed within 24 to 48 hours. Keep samples cool and deliver promptly.
- Flush an indoor tap for several minutes unless the lab instructs otherwise, and ask whether to sample at the kitchen tap or directly from the well system. For practical sampling do’s and don’ts, see Cornell’s home well sampling tips.
Reading nitrate results
If nitrate is above 10 mg/L as nitrogen (or above 45 mg/L as nitrate), treat it as unsafe for drinking. Boiling does not remove nitrate and can make levels higher by concentrating the water. Common carbon filters and standard softeners do not remove nitrate. For the federal standard, refer to the EPA’s drinking water rules, and for what does and does not work, see this summary of nitrate treatment performance from the Upper Republican NRD.
What to do if nitrate is high
Immediate steps for families
- Use bottled water or verified treated water for infant formula and for drinking by infants and pregnant people until the issue is resolved. Local programs sometimes provide replacement water in impacted areas; see the Valley Water Collaborative resources.
- If total coliform or E. coli are detected, stop using the water for drinking and cooking until you disinfect the well and retest. Homeowner guidance on actions after a positive result is available at wellowner.org.
Confirm and investigate
- Repeat the test to confirm a high result and consider a split sample with the lab.
- Contact Monterey County Environmental Health or the Central Coast Regional Board for next steps and potential source considerations. Regional contacts are listed under Groundwater Assessment & Protection.
Treatment options that work
Point of use vs whole house
- Point of use systems treat one tap, typically the kitchen sink. Reverse osmosis is common and can reduce nitrate significantly.
- Whole house systems treat all water entering the home. Nitrate removal is possible with anion exchange or large RO, but systems are more complex and costly.
See performance summaries for RO and ion exchange, and why boiling or standard carbon filters do not work, in this overview from the Upper Republican NRD.
Choosing and verifying a system
Work with a qualified water treatment professional and insist on NSF or ANSI certifications for nitrate reduction. After installation, retest to verify removal. The State Water Board lists recognized devices and homeowner guidance at the Residential Treatment Device program.
Longer term solutions
Some properties can blend water from a cleaner source or connect to a nearby public water system. Where nitrate is widespread, state and regional programs may provide replacement water or fund longer term fixes for communities. For program updates and replacement water news, see the State Water Board’s program announcements and local contacts at Groundwater Assessment & Protection.
Real estate tips for Prunedale buyers and sellers
If a Prunedale home uses a private well, plan for water testing early. Buyers commonly make well water testing a contingency that includes bacteria, nitrate, and locally relevant metals like arsenic. Share any recent test reports you have and be prepared to discuss mitigation options if something is elevated. For buyer test lists and timing guidance, see homeowner resources from wellowner.org, and contact Monterey County Environmental Health for any local requirements or recommendations.
Local contacts and programs
- Monterey County Environmental Health and Central Coast Regional Water Board. Regional guidance, testing initiatives, and contacts are posted under Groundwater Assessment & Protection.
- State Water Resources Control Board, GAMA Domestic Wells. Regional findings, private well information, and treatment resources are at the GAMA Domestic Well Project.
- Valley Water Collaborative. Testing and replacement water resources for eligible households are summarized on the resources page.
Have questions about testing during a sale, or want a local plan for your well before listing? Reach out to a neighbor who understands both water issues and the Monterey County market. Connect with Sergio Ruiz for practical guidance and a coordinated path from testing to closing.
FAQs
How often should a Prunedale well be tested for nitrates and bacteria?
- Test at least once a year for total coliform and nitrate, and more often if you have infants, are pregnant, or after any well service or flooding, per wellowner.org.
What nitrate level is considered unsafe for drinking in California homes on private wells?
- Treat results above 10 mg/L as nitrogen, or 45 mg/L as nitrate, as unsafe for drinking and take protective steps, according to the EPA’s drinking water rules.
What should I do right away if my Prunedale well tests high for nitrate?
- Use bottled or verified treated water for infants and pregnant people, repeat the test to confirm, and contact local health authorities for guidance; see the Valley Water Collaborative resources.
Which home treatment systems actually reduce nitrate from well water?
- Reverse osmosis and anion exchange are the most common residential options for nitrate reduction, while boiling and standard carbon filters do not remove nitrate; see the Upper Republican NRD summary.
Where can Prunedale homeowners find certified labs and trusted device information?
- Look for California ELAP certified labs and review the State Water Board’s Residential Treatment Device resources at the GAMA domestic wells page and regional contacts under Groundwater Assessment & Protection.
How much does basic well testing cost around Monterey County?
- A basic bacteria plus nitrate panel often costs about $100 to $200 and broader panels cost more, based on local examples like Alvarez Plumbing’s testing overview.
