If your property is on a private well — common around Hockessin, Pike Creek, the rural edges of New Castle County and across into Cecil County — you are operating a small private water utility. It has no operator but you.
That is not alarming, but it does carry an obligation that city customers do not have. The City of Newark tests its supply and publishes an annual report. Nobody does that for your well.
The testing schedule
Every year
Total coliform bacteria and E. coli. The basic safety test. Coliform indicates a pathway for surface contamination to reach your well — a compromised cap, a cracked casing, a failing seal. E. coli specifically indicates faecal contamination and needs immediate action.
Nitrates. Particularly important in areas with agricultural activity nearby, and in an area with septic systems. Elevated nitrate is a serious risk for infants under six months.
Annual is the minimum. If your well has a history of bacterial hits, test more often.
Every three to five years
A broader panel covering the things that change slowly and affect your plumbing as much as your health:
- Hardness — calcium and magnesium
- Iron and manganese — staining, taste
- pH — low pH corrodes fixtures and pipe
- Total dissolved solids
- Sulphur / hydrogen sulphide — the rotten-egg smell
- Lead — particularly where older plumbing or fittings are present
- Arsenic — naturally occurring in some geology
Test immediately when
- The taste, smell, colour or clarity changes
- Anyone in the household has recurrent gastrointestinal illness with no other explanation
- There has been flooding near the wellhead
- Work has been done on the well, the pump or the plumbing
- A nearby septic system has failed
- You are buying the property. Non-negotiable. Test before closing, not after.
- A new baby is coming into the house — nitrates specifically
Get an independent test
This is the most important practical advice in this article.
Use a state-certified laboratory. The Delaware Division of Public Health maintains information on certified drinking water labs, and your county extension office can point you to them.
Be sceptical of free water testing offered by companies that sell treatment equipment. The issue is not necessarily accuracy — it is that the person interpreting the result has a financial interest in one particular conclusion. A hardness reading that is unremarkable to a lab becomes "your water is very hard" in a sales conversation.
An independent test costs a fraction of a treatment system. Pay for it.
Reading the result
A lab report is a list of numbers against limits. Here is what typically drives a decision.
| Finding | What it means | Usual response |
|---|---|---|
| Coliform present | Contamination pathway exists | Shock chlorination, retest, find the cause |
| E. coli present | Faecal contamination | Stop drinking it, treat urgently, retest |
| Nitrate elevated | Agricultural or septic influence | Treatment; critical if infants present |
| Hardness high | Calcium and magnesium | Softener, if scale is actually bothering you |
| Iron present | Staining, metallic taste | Oxidising filter — not a softener |
| Manganese present | Dark staining | Oxidising filter |
| Low pH | Acidic, corrodes plumbing | Neutralising filter |
| Hydrogen sulphide | Rotten egg smell | Aeration or oxidation |
| Lead present | Plumbing or fittings source | Identify source, filter, replace components |
The two mistakes people make
Fitting a softener to an iron problem. A softener is designed for hardness. Put it on water with significant iron and it fouls, loses capacity and fails. Iron needs oxidation. These get confused constantly because both produce "bad water" complaints.
Getting the sequence wrong. Treatment stages have an order. Sediment filtration goes first, or the grit destroys everything downstream. Oxidation comes before softening where both are needed. A system with the right components in the wrong order underperforms, and that is the single most common fault we find in existing installations.
Your pump is a diagnostic instrument
Two things a well tells you that city supply does not.
Short cycling. A pump switching on and off every few seconds while a tap runs is nearly always a waterlogged pressure tank, not a failing pump. The tank holds a cushion of compressed air so the pump does not restart constantly; when the bladder fails, that cushion goes.
Act on it quickly. The tank is much cheaper than the pump, and while it is failing the pump is accumulating start cycles that will destroy it. Caught early this is a tank replacement. Ignored it becomes a pump replacement — and most of that cost is pulling the pump from the well.
Running when nothing is on. City customers detect leaks with the meter test: shut everything off, note the meter, wait two hours, read again. You have no meter — but you have a pump. If it kicks on when nobody is using water, something is drawing from the system. That is a leak, and it is worth chasing.
Protecting the well itself
Testing tells you what is in the water. These keep things out of it.
- Check the well cap. It should be intact, sealed, and sitting above grade. A cracked or loose cap is the most common contamination pathway.
- Keep the area clear. No chemicals, fuel, fertiliser or pesticide storage near the wellhead. Do not park vehicles over it.
- Slope the ground away so surface water runs off rather than pooling around the casing.
- Know where your septic system is relative to the well, and maintain it. A failing drain field near a well is the contamination scenario that matters most around here.
- Never mix well and public supply plumbing without proper backflow prevention.
If you are also on septic
Most well properties in this area are. It changes what belongs in your drains, because a septic system runs on live bacteria:
- No chemical drain cleaners. They kill the bacterial action the system depends on.
- No garbage disposal. It loads the tank with solids it was never sized for. We decline to install them on septic for this reason.
- Nothing labelled flushable. Wipes do not break down.
- Think about softener discharge. Backwash brine arriving at a biological system should be planned at installation, not discovered later.
- Watch your water volume. A leaking toilet can quietly overload a drain field, and with no meter nothing warns you.
The short version
Bacteria and nitrates every year. A full panel every three to five. Immediately on any change, any flooding, any work on the system, and before buying.
Use a certified lab, not a vendor offering a free test. Treat what the result actually shows rather than what someone wants to sell — and remember that iron needs oxidation, not softening.
More on well pumps, pressure tanks and treatment, or call (302) 412-1353 if your pump is short cycling. That one is worth not putting off.
Related questions
For an existing private well serving your own home, routine testing is generally not mandated — which is precisely why it gets skipped. Testing is typically required at specific moments instead: when a new well is drilled, and often during a property sale, particularly where a lender or the buyer requires it.
The absence of a requirement is not a statement that the water is fine. It reflects the fact that a private well is private property. Nobody else is responsible for knowing what is in it, which makes annual testing a sensible habit rather than a formality.
Use a state-certified laboratory rather than a hardware store strip kit or a free test offered by a company selling treatment equipment. The Delaware Division of Public Health maintains information on certified drinking water laboratories, and your county extension office can also point you to them.
Be particularly cautious about free testing from treatment vendors. It is not that the results are necessarily wrong — it is that the person interpreting them earns money from one specific conclusion. Pay for an independent test; it costs less than the equipment you might otherwise be talked into.
For a rough hardness reading, strips are adequate and genuinely useful for deciding whether a softener is worth investigating. For anything that matters to health they are not — bacteria, nitrates, arsenic and lead all require laboratory analysis, and no strip gives you a reliable number.
Treat strips as a screening tool that might prompt a real test, never as a substitute for one. A negative strip result tells you very little.