Rehabilitate when the well is structurally sound but its yield has fallen because the screen is clogged with iron, scale, bacteria or sediment; cleaning and redevelopment often restore much of its output. Drill a new well when the casing or grout has failed, the water has turned salty or poor, or the aquifer cannot supply enough. A recovery test is the first step either way.
Key points
- Recovery test first: is it the well or the pump?
- Sound well, clogged screen: rehabilitate.
- Failed casing or grout, salty water: replace.
- Deepening and new wells need VDH permits; the old well is sealed.
Wellborne helps owners across Suffolk and the surrounding area decide whether a weak well can be saved. A new well is a big investment, and many declining wells can be restored for much less. Some cannot, and spending on them only delays the inevitable.
Start with a recovery test
Before deciding anything, separate a well problem from a pump problem. With the pump pulled or running under observation, the static water level, the pumping level and the rate at which the level recovers after pumping are measured.
- Level holds and recovers quickly, but output is low: the pump is the problem, not the well.
- Level drops sharply and recovers slowly: the well has lost capacity.
If the well has a completion report, comparing today’s yield with the yield measured when it was drilled shows how much has been lost.
When rehabilitation is the answer
A well that is structurally sound but delivering less water usually has a clogged screen. Iron bacteria, iron and manganese deposits, mineral scale and packed fine sand all build up where water enters the well. The signs are a slow decline over years, orange or red slime, and sometimes sand.
Rehabilitation combines mechanical cleaning, surging, airlifting and bailing, with treatment chosen for the cause, then measures the yield again. It costs far less than a new well and needs no construction permit unless the well is deepened.
When a new well is the answer
- The casing is cracked, corroded or collapsing. Sediment, muddy water or debris at the taps can signal it.
- The grout seal has failed, letting surface water down the outside of the casing and causing recurring bacteria.
- The water has turned poor or salty. Near the coast, USGS reports water below roughly 150 to 200 feet under Virginia Beach is too salty to use, and heavy pumping can draw saltier water toward a well.
- The aquifer cannot supply enough, even with a clean screen.
- The well is an old bored or dug well with water quality problems; a drilled well to a deeper, protected aquifer is often the better long-term supply.
What about deepening?
Deepening is a middle path when the existing casing allows it and a useful aquifer lies below. It needs a VDH permit. In Suffolk, USGS mapping found the Yorktown-Eastover aquifer absent in the southwestern part of the city, so the next useful unit there may be far deeper. Deeper aquifers also tend to carry more sodium and natural fluoride, which may mean treatment.
Comparing the paths
| Rehabilitate | Deepen | New well | |
|---|---|---|---|
| Permit | Not for cleaning | VDH permit | VDH permit ($300) |
| Old well | Stays in service | Stays in service | Must be sealed (permit) |
| Fixes clogged screen | Yes | Not directly | Yes (new screen) |
| Fixes failed casing | No | No | Yes |
| Changes water source | No | Yes | Yes |
| Relative cost | Lowest | Middle | Highest |
What the records add
A completion report from when the well was drilled gives the original yield, depth, casing and screen. Comparing those with today’s measurements shows how much the well has changed and whether the screen sits where it should. Where there is no record, the measurements taken now become the baseline. In the Suffolk extension clinic, 18% of wells had been built before 1981, and older wells are the most likely to be missing records.
The decision in practice
Most decisions follow from three readings: the recovery test, the condition of the casing and the water quality. If the casing is sound and the water is good, rehabilitate first. If either has failed, a new well is usually the better use of money. For a well that is declining, call (757) 919-1972 and tell us what has changed.