Clear water is not always safe water. Some of the most serious contaminants found in private wells have no color, taste, or smell. You can drink the water every day without noticing anything unusual, yet laboratory testing may reveal bacteria, nitrates, arsenic, or another contaminant that requires attention.
This is especially important for well owners in Southern Oregon and Northern California. Our regional geology can contribute naturally occurring minerals and metals, while farms, livestock, septic systems, fuel storage, flooding, and wildfires can introduce additional risks.
At Enloe Drilling and Pumps, we believe well-water testing should be treated as routine property maintenance. You service your pump, inspect your pressure tank, and maintain your septic system. Testing the water should be part of the same process.
The right testing schedule depends on your location, the age and condition of your well, surrounding land use, and whether anything has recently changed. However, there are several core tests every private well owner should understand.
Which Well-Water Tests Should Be Done Every Year?
We recommend that private well owners establish an annual testing routine. Water quality can change even when the well has performed reliably for many years.
Heavy rainfall, drought, agricultural activity, a damaged well cap, septic problems, and changing groundwater conditions can all affect a well. Previous safe results do not guarantee that the water is still safe today.
Read our latest blog: What’s the Difference Between a Shallow and Deep Well?
Total Coliform and E. coli Bacteria
Total coliform bacteria are used as an indicator that surface water, soil, insects, or other contaminants may be entering the well. A positive total coliform result does not always mean someone will become sick, but it tells us that the well or water system may be vulnerable to contamination.
E. coli is more serious because it can indicate contamination from human or animal waste. This may happen because of a damaged well seal, flooding, surface runoff, an improperly located septic system, or a problem with the well casing.
Bacteria cannot reliably be identified by looking at, smelling, or tasting the water. A glass of contaminated water may appear perfectly clean.
Nitrates and Nitrites
Nitrates and nitrites deserve particular attention in agricultural areas and on properties with septic systems, livestock, or fertilizer use nearby. These contaminants can enter groundwater through manure, fertilizer, wastewater, and failing septic systems.
Like bacteria, nitrates are usually colorless, odorless, and tasteless. Testing is the only dependable way to know whether they are present.
Elevated nitrate levels are particularly dangerous for infants. Pregnant women and other vulnerable household members should also take the result seriously and obtain appropriate medical or public-health advice.
pH and Total Dissolved Solids
A pH test shows whether the water is acidic, neutral, or alkaline. Low-pH water can be corrosive. Over time, it may damage plumbing components and contribute to metals such as copper or lead entering the water from household pipes and fixtures.
High-pH or mineral-rich water may contribute to scale accumulation inside plumbing, pressure tanks, water heaters, and appliances.
Total dissolved solids, commonly called TDS, provide a broad indication of the amount of dissolved material in the water. A TDS result does not identify one specific contaminant, but an unusual result can signal that more detailed testing is needed.
Which Regional Contaminants Should Be Tested Periodically?
Annual bacteria and nitrate testing provides a good foundation, but it does not give you a complete picture. In Southern Oregon and Northern California, we recommend discussing a broader laboratory panel with a certified laboratory based on your property’s geology and surrounding land use.
Arsenic
Arsenic occurs naturally in groundwater in parts of the western United States. It does not announce itself through an unusual smell, metallic taste, or visible discoloration.
A well can produce water that looks and tastes excellent while still containing elevated arsenic. That is why we recommend including arsenic in an initial comprehensive test and repeating the test according to the laboratory’s or local health authority’s guidance. A two-to-three-year testing interval may be appropriate for many properties, but higher-risk wells may require more frequent monitoring.
Iron and Manganese
Iron and manganese are often associated with staining, sediment, unpleasant tastes, and discoloration. You may notice orange or brown marks from iron, while manganese may produce darker staining.
These minerals can also accumulate inside plumbing and water equipment. Although many iron and manganese problems are primarily aesthetic or operational, high concentrations still need to be assessed correctly. The treatment system must be selected according to the actual laboratory result and water chemistry.
Hardness
Hard water contains elevated concentrations of minerals such as calcium and magnesium. It may leave scale on fixtures, reduce the efficiency of water heaters, and shorten the service life of household appliances.
A hardness test helps determine whether a water softener is appropriate and, importantly, how that system should be sized. Installing treatment equipment without testing first often leads to disappointing performance and unnecessary expense.
Boron and Other Naturally Occurring Minerals
Depending on the local geology, a broader mineral analysis may include boron and other inorganic constituents. This can be especially relevant when well water will be used for irrigation, livestock, or agricultural production.
The correct panel should be based on how the water will be used. Drinking-water requirements are not always the same as the requirements for crops, irrigation equipment, or livestock.
Volatile Organic Compounds and Pesticides
A property near orchards, agricultural land, fuel tanks, workshops, industrial activity, or a known spill may require testing for pesticides or volatile organic compounds, also known as VOCs.
These tests are not always included in a basic well-water panel. You must tell the laboratory about the property’s history and nearby risks so it can recommend the correct analysis.
When Should Well Water Be Tested Immediately?
A routine testing schedule provides a baseline, but certain events should trigger immediate inspection and testing. If there is a reasonable possibility that the well has been contaminated, do not wait for the next annual test.
After Flooding or Heavy Rainfall
Test the water if floodwater reaches the wellhead, surface water pools around the casing, or heavy rainfall causes runoff to flow toward the well.
Floodwater can carry bacteria, sewage, animal waste, pesticides, and other contaminants. A flooded well should be inspected, disinfected where appropriate, flushed, and tested before the water is considered safe for drinking.
The initial laboratory panel will commonly include:
- Total coliform bacteria
- E. coli
- Nitrates and nitrites
- Additional contaminants associated with the specific flood or surrounding land use
After a Wildfire
Wildfires are a serious regional concern. Heat can damage wellheads, electrical components, storage equipment, and plastic pipes made from materials such as PVC or HDPE.
Burned or heat-damaged synthetic components may introduce VOCs or semi-volatile organic compounds into the water system. Fuel, oil, ash, firefighting runoff, and damaged storage containers can create additional contamination risks.
After a wildfire, turn off the pump’s electrical power before inspecting damaged equipment. Do not touch exposed wiring. Contact qualified professionals to evaluate the well, pump, electrical connections, pressure system, and buried or exposed water lines.
Depending on the damage, testing may include:
- VOCs and SVOCs
- A BTEX panel, which includes benzene and related fuel compounds
- Bacteria
- Heavy metals
- Other contaminants identified by local authorities or the laboratory
Do not assume that flushing or shock chlorination will remove chemical contamination. Damaged plastic components may need to be replaced before the system is disinfected, flushed, and tested.
After Well or Pump Repairs
Opening a well or removing a pump creates an opportunity for bacteria and debris to enter the system. Test the water after major well repairs, pump replacement, casing work, or any service that exposes the inside of the well.
The system may need to be disinfected before a follow-up bacteria sample is collected. Your contractor and laboratory should provide guidance based on the work performed.
When the Water Changes
Arrange an inspection and water test if you notice:
- A sudden change in color, taste, or odor
- Cloudy or discolored water
- Sand, grit, or unusual sediment
- Oily films or chemical odors
- New staining on fixtures or laundry
- A sudden reduction in water pressure
- A pump that runs continuously or cycles rapidly
A pressure change does not automatically mean the water is contaminated. It may be caused by the pump, pressure tank, pressure switch, plumbing, or a declining water level. However, a sudden operational change is a good reason to inspect the complete system and determine whether water-quality testing is also necessary.
When Household Members Become Ill
Test the water promptly if household members, regular visitors, or pets experience recurring gastrointestinal symptoms without an obvious cause. Symptoms such as diarrhea, nausea, and stomach cramps may have many explanations, but the drinking water should not be overlooked.
Stop using the water for drinking and food preparation until you receive appropriate advice and reliable test results.
How to Collect an Accurate Well-Water Sample
Incorrect sampling is one of the most common reasons for unreliable results. Laboratories measure some contaminants at extremely low concentrations. Touching the inside of a bottle, using the wrong faucet, or delivering a sample too late can compromise the analysis.
Always follow the laboratory’s instructions because collection procedures differ according to the contaminant being tested. A bacteria sample is not necessarily collected in exactly the same way as a metals or VOC sample.
1. Obtain the Correct Bottles From the Laboratory
Never collect a formal laboratory sample in a household water bottle, mason jar, food container, or bottle washed with dish soap.
Obtain a certified sampling kit directly from the laboratory. Different analyses may require different bottles, preservatives, fill levels, and handling procedures.
A bacteria bottle may contain a measured preservative or neutralizing agent. Do not empty or rinse the bottle unless the laboratory specifically tells you to do so.
2. Choose the Correct Sampling Faucet
Use a clean cold-water faucet that represents the untreated well water whenever possible. Avoid sampling through a garden hose, water softener, refrigerator dispenser, carbon filter, or reverse-osmosis system unless the purpose of the test is to evaluate water after that specific treatment device.
A simple fixed faucet is usually preferable to a pull-out spray head or swing-neck faucet. Remove the aerator or screen if the laboratory’s instructions require it.
3. Prepare the Faucet Properly
The preparation method depends on the test. For bacteria sampling, the faucet may need to be disinfected according to the laboratory’s instructions. For metals testing, a first-draw sample may sometimes be required instead of a flushed sample.
Do not apply one collection method to every bottle. Read the instructions for each test or ask the laboratory to explain the procedure.
4. Avoid Touching the Inside of the Bottle
Wash your hands before sampling. Do not touch the inside of the bottle, cap, or bottle opening. Place the cap on a clean surface only if the laboratory instructs you to do so, although holding it with the inside facing downward is often safer.
Fill the bottle to the required level. Do not overflow a bottle containing preservatives, and do not leave unnecessary headspace in a VOC vial. The laboratory kit should explain the correct fill method.
5. Label and Deliver the Sample Promptly
Record the sampling location, date, time, and any other information requested by the laboratory. Keep samples chilled with ice packs when instructed, but do not allow them to freeze.
Bacteria samples have strict holding times. Plan the collection around the laboratory’s opening hours or courier schedule. A perfectly collected sample can still become invalid if it arrives too late.
What Should You Do If the Water Fails a Test?
Do not panic and do not purchase treatment equipment based on one number you do not fully understand. First identify the contaminant, confirm the result where appropriate, inspect the well system, and investigate the likely source.
The correct response depends on whether the result represents an immediate health risk, a long-term health concern, or an aesthetic and operational problem.
Positive Bacteria Results
If E. coli or another serious bacterial problem is detected, stop drinking the water. Follow your local health authority’s instructions regarding bottled water or boiling water for drinking, cooking, brushing teeth, and making ice.
The next steps may include:
- Inspecting the well cap, casing, seals, and surrounding drainage.
- Checking for flood entry, insects, cracks, or nearby septic problems.
- Shock-chlorinating the well and household plumbing when appropriate.
- Flushing the system thoroughly.
- Waiting for the period recommended by the laboratory or health authority.
- Collecting a follow-up bacteria sample.
If bacteria return after proper disinfection, the problem may be structural or the groundwater source may face continuing contamination. The solution could involve well repairs, improved drainage, a sanitary well seal, continuous disinfection, or another site-specific intervention.
Elevated Nitrates or Nitrites
Do not boil water containing elevated nitrates. Boiling removes water through evaporation and may concentrate the contaminant.
Use an alternative drinking-water source while the result is being assessed. Investigate possible sources such as fertilizer, manure, septic leakage, or shallow groundwater contamination.
Shock chlorination does not remove nitrates. Treatment may involve a properly certified reverse-osmosis or ion-exchange system, depending on the concentration and amount of water that must be treated. The treated water must be tested regularly to confirm that the equipment is working.
Elevated Arsenic
Arsenic requires treatment specifically certified and sized for arsenic reduction. Depending on the water chemistry and the form of arsenic present, the solution may include adsorption media, reverse osmosis, oxidation followed by filtration, or a combination of treatment methods.
There is no universal arsenic filter that works equally well for every well. Other water characteristics can interfere with treatment, so the system should be selected using a complete laboratory analysis.
Iron, Manganese, and Sediment
Iron, manganese, and sediment problems may be treated with oxidation, filtration, settling, or other equipment selected for the actual water chemistry.
Before installing a filter, it is important to determine whether the sediment is coming from the natural formation, damaged casing, an incorrectly positioned pump, excessive pumping, or another mechanical problem. Treatment equipment will not correct a failing well structure.
Hardness or Low pH
Hardness may be managed with a correctly sized water softener. Low-pH water may require an acid-neutralizing system using media such as calcite.
These systems change the water chemistry and can affect pressure, flow, maintenance requirements, and other treatment equipment. The whole system should be considered before installation.
Wildfire-Related VOCs
Shock chlorination does not remove VOC contamination caused by burned plastic, fuel, or chemicals. Damaged piping and components may need to be replaced.
Depending on the laboratory results, treatment could include activated carbon or another technology designed for the identified chemical. Severe contamination may require a different water source while the system is repaired and repeatedly tested.
A Well Can Produce “Perfect” Water and Still Have a Problem
One of the best examples of why testing matters is a rural property transaction in Jackson County, Oregon. The water appeared clean, tasted good, and had no noticeable odor. From the buyer’s perspective, everything seemed perfect.
However, appearance tells you nothing about invisible contaminants such as arsenic, nitrates, or bacteria. This is precisely why Oregon law requires testing during qualifying real-estate transactions involving a domestic well.
Under Oregon’s Domestic Well Testing Act, when an offer is accepted on qualifying real estate served by a domestic well, the seller must arrange testing for arsenic, nitrates, and total coliform bacteria and share the results as required. Certain properties and well types may be exempt, so buyers and sellers should confirm the requirements that apply to their transaction.
The important lesson is simple: never allow good taste, clear water, or years without an obvious problem to replace proper testing.
What Should You Check Before Buying a Property With a Well?
A well is a major property asset, but buyers need more than a basic bacteria result. You need to understand both water quality and system performance.
Before completing the purchase, consider requesting:
- A laboratory water-quality analysis appropriate to the property
- A well-flow or yield test
- Static and pumping water-level measurements
- An inspection of the wellhead, cap, casing, and sanitary seal
- An assessment of the pump, pressure tank, controls, and electrical components
- Available drilling logs and maintenance records
- Information about nearby septic systems, agriculture, fuel storage, and previous land use
A water sample tells you what was in the water at the time of collection. It does not tell you whether the pump is correctly sized, whether the well can meet the household’s peak demand, or whether the equipment is close to failure. Water-quality testing and a mechanical well-system inspection serve different purposes, and both matter.
Why Pump Selection Affects Water Quality and Reliability
A pump should be selected according to the well’s depth, diameter, yield, pumping water level, intended demand, and pressure requirements.
Installing a pump that can withdraw water faster than the well recovers may cause the water level to fall excessively. In some wells, this can contribute to sand, silt, air, reduced flow, dry-run damage, or poor system performance.
A correctly designed system may include:
- A properly sized submersible or turbine pump
- Suitable drop pipe and electrical cable
- Reliable check valves positioned according to system requirements
- A correctly sized pressure tank
- Dry-run or low-water protection
- Controls matched to the pump and expected demand
Check valves help maintain the water column and prevent unwanted reverse flow when the pump stops. Their number and placement must follow the pump manufacturer’s requirements and the design of the complete system.
How Often Should You Test Your Well Water?
As a practical starting point, we recommend the following schedule:
- Test for total coliform bacteria, E. coli, and nitrates every year.
- Consider annual pH and TDS testing to monitor changes in general water chemistry.
- Complete a broader mineral and metals panel when the well is new, when buying a property, and periodically thereafter.
- Discuss arsenic testing frequency with a certified laboratory or local environmental health department.
- Test for pesticides, VOCs, or fuel-related compounds when the property’s location, history, or a recent incident creates a specific risk.
- Test immediately after flooding, wildfire damage, significant well repairs, or an unexplained change in the water.
- Retest treated water regularly to confirm that filtration or treatment equipment continues to work.
California recommends annual water-quality testing for domestic wells used as a drinking-water source. In both California and Oregon, your county environmental health department and an accredited laboratory can help identify additional contaminants of concern in your specific area.
Professional Water Well and Pump Services in Southern Oregon and Northern California
Testing tells you what is in your water. A complete well-system assessment helps determine how the problem entered the system and what should be done about it.
Enloe Drilling and Pumps is a multigenerational, family-owned company with a drilling history dating back to 1913. We provide water well drilling, pump installations, pump repairs, well testing support, pressure-system services, and system upgrades for residential, agricultural, and commercial properties.
We serve Siskiyou and Shasta counties in Northern California, as well as Klamath, Jackson, and Josephine counties in Southern Oregon.
If you are buying a rural property, planning a new water well, replacing an aging pump, or investigating a change in your water supply, contact Enloe Drilling and Pumps for professional guidance and a site-specific assessment.
Call 530-964-2807 or 541-841-4124 to request a free quote for water well drilling or pump installation and repair services in Southern Oregon and Northern California.