Well pump advice needed

[PaulM3]

It is time to replace my well pump and looking for advice. I have a dug well. The original boring is 64 feet but recently verified at 61 feet (after 35 years of silt). The static water level is at 32 feet. This is a low yield well (approx. 3 gpm). Casing is 24" diameter.

I plan to install a 240V submersible pump. The current 110V jet pump (2 line) ready for replacement. I am less concerned about cost as I am about efficiency and longevity. The pump will supply the house, as well as several outdoor agricultural style hydrants.

Looking for advice on horsepower requirements, specific features I should look for or consider, and pressure switch/tank/etc. requirements and recommendations. Due to the low yield, self priming is a must.

More background: the current jet pump is in the well casing, pressure switch is on the pump, pressure tank is about 100 feet away in the house with minimal elevation change from pump to tank. Given the current setup, I am not opposed to relocating some or all of the components if appropriate. For instance, the location of the pressure tank or the pressure switch. The house is 2-story with 3 full baths along with normal washer, dishwasher, etc.

I have adequate plumbing experience, have worked on the existing pump, replaced pressure tanks, etc. as well as installed all hydrants.

Thank you.

Paul

 

[Reach4]

Looking for advice on horsepower requirements, specific features I should look for or consider, and pressure switch/tank/etc. requirements and recommendations. Due to the low yield, self priming is a must.

1/2 HP 10 gpm.

This is one pump where you could use at 40/60 psi.

For a 10 gpm pump, you would want a 44 gallon or bigger pressure tank, unless you use a CSV.

 

[Sponsor]

 

[Valveman]

Like Reach says a 1/2HP, 10 GPM submersible controlled with a PK1A kit would give you strong constant pressure and last a long time. However, you might want to consider a storage or cistern tank system, as that would give you more flexibility for irrigation. Either way you would probably also want a Cycle Sensor on the well to protect the pump from running dry. Sub pumps are self priming but don't last long when running dry.

 

[Reach4]

At 23.5 gallons per ft, if the pump is set at 45 ft, maybe no Cycle Sensor needed I would think, unless that well is an incredibly slow producer. But maybe it is. An alternative would be to put a float switch at the pump to inhibit the pump when the water level dropped. Another alternative would be to have a float switch controlling an alarm to tell you to stop using water at a high rate when the well is low.


For sure you want a flow inducer on the pump. Cheap. Homemade. Easy. If you have trouble finding info on building that, let us know. The search box above should help.

Is freezing a consideration? It is possible to use a pitless adapter in a dug well, but maybe you are in the no-hard-freeze part of Virginia.

 

[PaulM3]

Thanks all for the replies. A couple of follow up questions and information.

We are in zone 7a (Spotsylvania County) so we do occasionally get a hard freeze. Hence the pressure tank not in the well casing.

Current pressure tank is 42 gal. based on space. However, I can relocate from the crawl space to basement and remove all size limits.

I am currently running at 40 psi.

Depending on the season, recharge ranges from 3gpm to more often, 2.4gpm. Static water level also fluctuates by a few feet. Running the pump as low as possible is my solution, knowing that once I run for a while at high volume, I need to build in some recharge time.

I see agreement on the 1/2 hp, 10 gpm pump. Does your recommendation change if I wanted to drop the pump to 50 feet or even 55 feet (as opposed to 45 feet)? What if I wanted to add a storage tank in the future (something I thought about and would have been a followup question)? The chart above indicates nothing changes.

Reach4, I will look up the flow inducer and let you know if I have questions.

I also like the idea of a float switch to protect the pump. Automatic protection is better than relying on human intervention.

 

[Valveman]

A 10 GPM, 1/2HP will still work fine from 50'. Cycle Sensor to protect the well pump is better than a float switch, but you could use either for a booster pumping from a tank. Several ways to add a storage tank later. This one lets yo draw water from the well and/or the booster in the storage tank.