Low-yield well solutions and options

A low-yield well that runs short during the morning rush is frustrating, but there are proven solutions, and it is not necessarily a failed well. Many low-yield wells serve households well once demand and storage are matched to what the well can supply. This page sets out the options, roughly from least to most disruptive.

What is a low-yield well?

Penn State Extension defines low-yielding wells as wells that cannot meet the peak water demand for the home or farm, and says an adequate water system must yield enough water to satisfy peak demand for at least 2 hours. Peak periods usually last 30 minutes to 2 hours in the morning or evening. Penn State Extension: Using Low-Yielding Wells To see how your well compares, read how many gallons per minute a well should produce. [PSU-LOWYIELD source note]

Why is my well low-yield?

A falling supply can be a weak aquifer, a well whose openings have clogged, or a pump problem. Have a contractor measure the yield and compare it with the original well log. A decline over time points toward rehabilitation; a well that was always weak points toward storage or demand changes. See signs your well is running dry for the diagnosis steps.

Option 1: reduce peak demand

The options generally fall into two categories: reducing peak water use or increasing storage. Spreading water-using activities through the day and conserving water both help, and installing water-saving devices can reduce household water use by up to 30 percent. Penn State Extension: Using Low-Yielding Wells [PSU-LOWYIELD source note]

Option 2: add a well storage tank

Source for the table: Penn State Extension: Using Low-Yielding Wells. The same article describes borehole storage as less predictable and often more expensive than a storage tank. Connecticut guidance adds a practical point: above-ground tanks with drain valves remain usable during power outages, while borehole storage does not. Connecticut DPH: Private Well Guidance for Determining Well Safe Yield (2009) [PSU-LOWYIELD source note] [CT-SAFEYIELD source note]

Option 3: rehabilitate the well

If the well once produced more, its openings may be clogged by encrustation, iron or manganese bacteria, or fine sediment. Rehabilitation methods include chemical treatment, hydrofracturing, high-pressure jetting and surging, and the best results often combine chemical and mechanical methods. NGWA (Wellowner.org): Restoring Flow through Water Well Rehabilitation Penn State Extension notes that a yield decrease of 25 percent or more generally indicates rehabilitation is in order, and that delaying it can raise costs or make it impossible. Penn State Extension: Water Well Maintenance and Rehabilitation [NGWA-RESTORE source note] [PSU-REHAB source note]

Option 4: deepen or replace

Deepening adds storage and may reach more water, but it can also change water quality significantly. Penn State Extension: Using Low-Yielding Wells A new well is the most expensive option and still carries the risk of another weak hole. Weigh them in deepen an existing well or drill a replacement. [PSU-LOWYIELD source note]

How a storage system works

A typical low-yield setup has two stages. The well pump runs at a gentle rate the well can sustain, often controlled so it never draws the water below the intake, and fills a storage tank over the day. A second (booster) pump draws from the tank and pressurizes the house through a normal pressure tank. The house sees full flow at peak times even though the well supplies water slowly.

Ask your installer about:

• Tank size, using the 100-gallons-per-person rule of thumb as a starting point. Penn State Extension: Using Low-Yielding Wells
• Low-water protection so the well pump stops before the well runs dry.
• Sanitation, since stored water needs a covered, cleanable tank and periodic disinfection.
• Power outages, when a booster pump won't run without backup power.

Then confirm the well's sustained rate with a proper yield test; see well pump tests.

How do you size a low-yield well system?

Whatever you choose, the pump and tanks should be sized to the tested yield and your peak demand. See planning a pump for a new well.