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MULTIPLE BUILDINGS ON A SINGLE WELL
SYSTEM
There are many areas, especially in
vacation communities, where several homes are connected to a single
well. When planning a system like this, Well Manager® can provide
amazing performance using wells that would normally be considered
inadequate.
Excluding outside water use for things
like landscape watering and car washing, the chart below shows the daily
requirement based on industry standard allowances next to the amount of
water that can be harvested from wells of various yield.
You can see that, according to industry
standards, 10 people need only 750 gallons of water to cover their
indoor water needs. A ¾ gallon per minute well produces nearly enough to
supply that many people. That being the case, a 5 gallon per minute
well, operated by a Well Manager®, should be more than twice the water
needed to supply 10 homes with 4 occupants each.
Sizing a Well Manager to run such a
system might go something like this. Let us assume that peak demand will
occur between 6AM and 7AM in the morning.
Each family will require:
| 4
showers @10 min x 3 gpm = 30 gal x 4
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=120 gallons |
| 8 toilet flushes @
3.5 GPF
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=28 gallons |
| 4 tooth brush, shave, face wash @ 3
gal
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=12 gallons
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| 1 Load clothes in washer
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=15
gallons |
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175 gallons in an hour |
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| Ten houses would require
10 x 175.00 |
= 1,750 gallons |
| Adding a 20% safety
factor
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+ 350 |
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2,100 gallons |
A 5 gpm well can contribute 5 x 60 = 300
gallons in one hour Leaving a storage requirement of 1,800 gallons
One of the many available 2500 gallon
tanks measures 90" diameter x 100" High. This will fit through an 8'
opening and sit comfortably in a well house. The next chore is to
determine what sort of peak demand flow rate needs to be provided.
The 10 houses are all 2 ½ bath homes with
laundry and kitchen.
| Each house has 2 showers at 3 gpm
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= 6 gpm |
| The washing machine may
be filling |
= 4 gpm |
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10 gpm for each house x
10 =100gpm |
The worst case scenario would require no more than 100 gpm and
the odds of all the showers and all of the washers running at the same
time is remote. Two 60gpm pumps controlled by a lead - lag alternator
would provide more than adequate flow and redundancy so service wouldn't
be interrupted if one pump were to fail. Since one pump won't keep up
with peak demand, residents should notice a lack of pressure and find
the bad pump when they investigate.
If water use was close to that figured
above and the 2500 gallon tank was full at 6:00 AM:
| Used in one hour |
-1,750 |
| Collected in one hour
|
+ 300 |
| Used from storage by
7:00 AM |
1,450 gallons |
Time required for a 5 gpm well to refill the tank 1450 ÷ 5 = 290
min or 290 ÷ 60 = 4.83 hrs. Barring other large water uses, this tank
will be full sometime between 11:00AM and noon. This means that the full
potential of this well is not going to be needed.
What is the full potential of this well?
The well yield is 5 gpm and there are 1440 minutes in a day so the
maximum daily yield of this well is 5 x 1440 = 7,200 gallons or a little
more than 4 times the amount needed to supply these homes.
If an additional safety margin were
required to allow for leaks and running toilets, a larger or second tank
could be used.
SEE ALSO:
INSURING SUSTAINABILITY OF
PERFORMANCE IN WELL SUPPLIED SYSTEMS BY LIMITING WITHRAWALS
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