If you are buying a home in Dewey-Humboldt or you already live on a private well, you might be wondering how to make sure your water is safe. Groundwater quality can change without warning, and different wells in the same area can produce very different results. In this guide, you’ll learn what to test, how to collect samples correctly, and which filtration options work for the most common issues here. Let’s dive in.
Why Dewey-Humboldt wells need testing
Dewey-Humboldt is a semi-rural part of Yavapai County where many homes rely on private wells. Local geology can introduce naturally occurring metals, including arsenic, into groundwater. Shallow wells near septic systems, livestock, or fertilizer use also face higher risks for nitrate and bacterial contamination.
Private wells are not regulated under federal drinking water law. That means testing and treatment are your responsibility. Prioritize bacteria, nitrate, and arsenic to protect your household and to document water safety if you plan to sell.
What to test first
Bacteria: total coliforms and E. coli
Bacteria are a top priority because they can signal recent fecal contamination. Any detection of E. coli requires immediate action. Total coliforms are an indicator that contamination pathways may exist, so you should confirm with follow-up sampling and investigate the cause.
Nitrate
Nitrate often comes from fertilizers or septic systems. High levels can be dangerous for infants and pose risks during pregnancy. The key reference level is 10 mg/L as nitrogen. Compare your result to the units listed by the lab so you use the correct threshold.
Arsenic
Arsenic occurs naturally in parts of Arizona. Long-term exposure increases health risks even at low levels. The EPA reference level for arsenic in drinking water is 10 µg/L. If your results are close to that level, consider treatment for drinking water.
How to test and when
Sampling frequency
- Bacteria: test at least annually and after well repairs, flooding, long absences, or any change in taste, color, or odor.
- Nitrate: test at least annually. Test more often if your well is shallow, near agriculture or septic systems, or if your household includes infants or pregnant women.
- Arsenic: test at least once when you take ownership, then every 2 to 5 years if levels are low. Test annually if levels approach 10 µg/L or after installing treatment.
Proper sampling basics
Use bottles supplied by a certified lab. Follow their instructions exactly because collection methods differ by contaminant. For bacteria, labs usually provide a sterile bottle, request collection from an indoor tap connected directly to the well, and ask you to refrigerate the sample and deliver it the same day.
For nitrate and arsenic, the lab may provide specific containers, preservatives, or temperature requirements. Record the well ID, date, time, weather, and any recent well work. If you plan to use results in a property transaction, ask the lab about chain-of-custody steps.
Where to get supplies and guidance
You can get bottles and instructions from certified commercial labs or the state public health lab. Local resources include Yavapai County Environmental Health and the University of Arizona Cooperative Extension. You can also contact the Arizona Department of Health Services Laboratory Certification Program to confirm the lab is certified for the analytes you need.
Choosing the right filtration
The right system depends on which contaminants are present, how you use your water, and your maintenance preferences. In general, you use point-of-entry systems for whole-house needs and point-of-use systems at a kitchen tap for drinking and cooking.
If bacteria are present
- Immediate steps: If E. coli is detected, do not drink the water. Use bottled water or boil water for drinking and food preparation. Shock chlorinate the well and plumbing or hire a well contractor to do it.
- Fix the cause: Inspect the well cap, casing, and drainage. Check nearby septic systems and possible surface water intrusion.
- Ongoing treatment: Consider continuous chlorination or a whole-house UV disinfection unit. UV works well if water is clear and low in iron and turbidity. Both options require regular maintenance and monitoring.
- Verify: Retest after disinfection and again after system installation.
If nitrate is high
- Short term: If nitrate is above 10 mg/L as nitrogen, avoid using the water for infant formula and advise pregnant women to use an alternative safe source.
- Treatment: A point-of-use reverse osmosis unit is a common, effective choice for drinking water. Anion exchange systems can be sized for whole-house use, but you will need to manage brine discharge and maintenance.
- Verify: Retest treated water and check system performance at least annually.
If arsenic is high
- Treatment: Point-of-use reverse osmosis is a reliable solution for drinking water. Adsorptive media systems or anion exchange can be used at the tap or for the whole house, depending on your goals.
- Important detail: Many media work best on arsenate, also called As(V). If your water contains arsenite, As(III), you may need pre-oxidation to convert it before removal. A qualified vendor can explain how their system addresses arsenic species.
- Verify: Test both before and after treatment on a schedule recommended by the vendor.
Simple decision guide
Bacteria
- E. coli detected: Stop using for drinking, disinfect well, retest, then consider continuous disinfection or UV if problems persist.
- Total coliforms only: Resample to confirm, look for structural issues, and correct the cause if repeat tests are positive.
Nitrate
- At or below 10 mg/L as nitrogen: Retest annually.
- Above 10 mg/L as nitrogen: Use an alternative safe source for infants and pregnant women. Install reverse osmosis at the kitchen tap or an anion exchange system, then retest.
Arsenic
- At or below 10 µg/L: Retest every 2 to 5 years.
- Above 10 µg/L: Install a point-of-use RO unit or a certified arsenic removal system, confirm the design addresses As(III) and As(V), then test after installation.
Budget and maintenance tips
Testing costs vary by lab and analyte. A basic bacteria test is often modest, while expanded panels with nitrate and metals cost more. Treatment prices depend on system type, capacity, and installation. Ask vendors for written performance data, third-party certifications, and a maintenance schedule.
Plan for routine tasks like filter changes, lamp replacements for UV, media changeouts for adsorptive systems, and resin regeneration for ion exchange. Keep a binder with test results, installation records, and maintenance logs. This protects your household and simplifies things if you ever sell.
Buying or selling a home with a well
If you are purchasing a home, test the well early in your inspection period. Ask for recent results and service records. For sellers, proactive testing and clear documentation can reduce friction and build trust with buyers.
If you need help coordinating local testing or contractor referrals, reach out. As a community-based resource, we can point you to certified labs, well professionals, and treatment vendors, and we will make sure you understand your options.
Ready to talk through a plan for your Dewey-Humboldt property or preparing to list? Connect with Josh Day Real Estate for local guidance, contractor referrals, and a smooth path to closing. Get a Free Home Valuation to understand how your well documentation supports your sale.
FAQs
What should I do first if E. coli is found in my Dewey-Humboldt well?
- Stop using the water for drinking or cooking, shock chlorinate the well and plumbing, then retest; consider continuous chlorination or a UV system if contamination persists.
How often should I test a private well in Yavapai County?
- Test bacteria annually and after well work or flooding, test nitrate annually, and test arsenic at least once then every 2 to 5 years or more often if levels are near the action level.
Which filtration removes arsenic from Arizona well water?
- Point-of-use reverse osmosis is effective, and adsorptive media or anion exchange can work if properly designed and maintained, often with pre-oxidation for As(III).
Do I need a whole-house system for nitrate or arsenic?
- Not always; many households choose a point-of-use system at the kitchen tap since ingestion is the main exposure pathway for nitrate and arsenic.
Where can I find certified labs for well testing in Arizona?
- Check with the Arizona Department of Health Services Laboratory Certification Program, Yavapai County Environmental Health, or the University of Arizona Cooperative Extension for lab lists and sampling guidance.
