Another Well Problem

[Travelover]

I'm starting a new thread about the same well that had suddenly provided brown water. Thankfully the water has cleared but I have a new issue.

Currently, I'm getting the sprinkling system ready and now find that the well will not maintain more than 25-ish PSI when any zone is running. For the past 5 years, the pump would hold a steady 40 to 45 PSI while any zone was operating. The well pumps up to 60 PSI fairly quickly during normal household use. It has a 40 to PSI control switch. The sprinklers have been off since October as I live in the Pacific Northwest area.

It occurs to me that I might have slime bacteria partially blocking the well pump intake, the drop pipe might be leaking or the pump itself may be weak. The 3/4 HP pump draws 7.5 amps at 240 volts, which is unchanged.

I'm fishing for ideas / tests that I can make myself before I open my wallet for the pump to be pulled. The well guy who replaced the capacitor intimated that it was probably put in with rigid PVC pipe, as his company installed it years ago and that is their practice. I have not confirmed that, but in any case I'm not up to pulling it myself.

Thanks in advance for any advice.

 

[ponytug]

Can you share how the system is plumbed? I.e. well->2" 75' pipe to house-> to check valve -> to pressure tank -> 2" manifold to house and sprinklers -> 100' 3/4" pipe run to sprinklers?

Did you flush the pressure tank after the brown water episode?
Has the length of the typical house (pressure tank) cycle changed?

I'm guessing that the brown water may have been a sediment intrusion in the well and your pump may be somewhat buried in sediment. Guess! If you do pull the pump, have your well folks check out the casing with a horoscope, and if the casing is ok, clean the well out before replacing the pump.

All the best,

Peter

 

[Travelover]

Can you share how the system is plumbed? I.e. well->2" 75' pipe to house-> to check valve -> to pressure tank -> 2" manifold to house and sprinklers -> 100' 3/4" pipe run to sprinklers?

Did you flush the pressure tank after the brown water episode?
Has the length of the typical house (pressure tank) cycle changed?

I'm guessing that the brown water may have been a sediment intrusion in the well and your pump may be somewhat buried in sediment. Guess! If you do pull the pump, have your well folks check out the casing with a horoscope, and if the casing is ok, clean the well out before replacing the pump.

All the best,

Peter

The well has a T at the head and 1" rigid PVC heads into the garage with pressure tank about 50 feet away. The other discharge is to a vacuum breaker, then to 1" PVC that runs all over the property, some zones are 300 feet away. This has worked fine for the 5 years I've lived here.

I did not flush the tank after the brown water episode. The pressure tank cycle seems a little slower than previously.

Attached is the well test from when I bought the place. Well is apparently 130 feet, not sure how to interpret the static level and draw down numbers.

 

[ponytug]

The well has a T at the head and 1" rigid PVC heads into the garage with pressure tank about 50 feet away. The other discharge is to a vacuum breaker, then to 1" PVC that runs all over the property, some zones are 300 feet away. This has worked fine for the 5 years I've lived here.

I did not flush the tank after the brown water episode. The pressure tank cycle seems a little slower than previously.

Attached is the well test from when I bought the place. Well is apparently 130 feet, not sure how to interpret the static level and draw down numbers.

As you describe the plumbing, I am missing something. If there is a vacuum breaker on the line to the sprinklers, that would leave them with no pressure, except when the pump runs. Could it be that there is a check valve after the vacuum breaker and that is where the T to the house and to the sprinklers happens?

The draw down is literally that. While pumping, usually after pumping for some number of hours at a stated gpm, the drawdown is the the depth after the pumping, in your case a 4' drop. The takeaway is that you can probably pump for awhile at 7gpm, because if the well is 130' deep, the pump is probably around 125', so you still have 47' of water over the pump at the end of the drawdown test.

I would point out that the number of hours of the drawdown test that the driller pumped is missing, as is the rate for the number of hours, as is the depth of the pump in the well. That information may be on file in your local county office, or from the folks who drilled the well.

More typically, the information is given as "pumping at 20gpm for four hours, a drawdown to X feet was observed." Sometimes the results are reported as a series of flows (gpm), and depths over time, e.g. 24hours. A lot depends on your local aquifer hydrology; if the well is in bedrock, drawdowns will tend to be large, if you are in sand, there won't be much. A relative has a 400' well straight into granite and all of the water seeps in from cracks in the bedrock, so 200' drawdowns aren't uncommon there, but the available water may only be 1,500-2,000 gallons per day.

Generally, the pumps occupy so much of the well casing the you have to pull the pump to clean the well.

Sorry.

All the best,

Peter

 

[Valveman]

The sprinkler pressure is low, but the well is not being pumped dry. So, the well screen and well are making plenty of water. The muck in the water could have damaged the impellers so they will not perform like they once did. Or, there could be muck in the pump screen or impellers. Or, a 20 PSI decrease in pressure could come from the water level in the well being 46' deeper than before. My guess is the impellers are damaged from the sediment as there is very little tolerance between the impeller and diffuser, and sediment makes the gap too wide. You could reduce the size of the sprinkler zones or reduce the size of nozzle in the sprinklers and get the pressure back up. A 3/4HP should max out at about 8.4 amps, which 7.5 amps makes me think the pump is worn. But the low amps could also be from a deeper water level or a blockage. If you pull the pump and don't find anything wrong, replacing with a larger pump or resizing the sprinkler zones will be needed.

 

[MossRoad]

If you can build pressure in the house side of the T, but can't build pressure in the sprinkler system side of the T, I can only think that:

1. The pump can build pressure with the low flow of the house side but can't provide the full flow on the sprinkler side.

2. There may be an underground leak somewhere on the sprinkler side that's thwarting your attempt to build pressure.

3. The pump is worn or partially blocked and won't provide the full flow.

I'd pull the pipe past the vacuum breaker and see how much unrestricted flow you have in Gallons Per Minute. If that was satisfactory, I'd try each sprinkler zone to see if all of them fail to build pressure, or just one of them. If just one fails, it's obvious. If all of them fail, there could be a leak between the vacuum breaker and manifold for the zones, or you're back to the pump not being able to provide full flow at pressure.

 

[etpm]

I'm starting a new thread about the same well that had suddenly provided brown water. Thankfully the water has cleared but I have a new issue.

Currently, I'm getting the sprinkling system ready and now find that the well will not maintain more than 25-ish PSI when any zone is running. For the past 5 years, the pump would hold a steady 40 to 45 PSI while any zone was operating. The well pumps up to 60 PSI fairly quickly during normal household use. It has a 40 to PSI control switch. The sprinklers have been off since October as I live in the Pacific Northwest area.

It occurs to me that I might have slime bacteria partially blocking the well pump intake, the drop pipe might be leaking or the pump itself may be weak. The 3/4 HP pump draws 7.5 amps at 240 volts, which is unchanged.

I'm fishing for ideas / tests that I can make myself before I open my wallet for the pump to be pulled. The well guy who replaced the capacitor intimated that it was probably put in with rigid PVC pipe, as his company installed it years ago and that is their practice. I have not confirmed that, but in any case I'm not up to pulling it myself.

Thanks in advance for any advice.

Do you have slime in your toilet tanks? If so then you could have slime on your pump and in all your pipes. Do you even chlorinate your well? I do mine about once a year because of the slime. If you have never chlorinated your well you may be surprised if you do because of all the brown water that comes out of the taps. This is a natural occurrence and is a reaction of the chlorine and the slime.
Eric

 

[Travelover]

Do you have slime in your toilet tanks? If so then you could have slime on your pump and in all your pipes. Do you even chlorinate your well? I do mine about once a year because of the slime. If you have never chlorinated your well you may be surprised if you do because of all the brown water that comes out of the taps. This is a natural occurrence and is a reaction of the chlorine and the slime.
Eric

This is a major question for me. Though I don't seem to have slime in the house, I've heard that when a well's usage is reduced (like no sprinklers for the winter) slime can accumulate on the pump's inlet screen and create a blockage. I can do the well chlorination myself, though I have not yet done it.

 

[steve tym]

Be careful chlorinating the well, it will make a mess of the water. Flush it from the bottom of the tank, not through the house.
I agree, the pump may be plugged, or worn. Max amps on a Franklin .75 hp motor is 8.0 amps. If it's a Pentek motor, it will be less. In my area, Franklin is the most common. 130ish' is pretty shallow for a 3/4. I'm still looking for leaks.

 

[Thomas]

Had some what same issue with brown water,supply line under ground had 1/2" crack,weem when pump was pushing water crack would open just enough allow ater mix with dirt...we were lucky to find problem quickly.