1. An introduction to Private Water Systems
Wells
Springs
Cisterns

2. Private Water System Regulations
No state requirements for construction, maintenance, treatment, etc.
No ownership of water
“Reasonable use” of water allowed
Little protection for existing sources
Deepest well and biggest pump wins

3. Impermeable layer (aquitard)
Wells and Springs Utilize Groundwater Aquifers
40 inches of precipitation
Well
Recharge
(12-15 inches)
Spring
Groundwater feeds
streams
Groundwater
Flow
Well
Aquifer #1
Impermeable layer (aquitard)
Aquifer #2

4. Pennsylvania Aquifers
Sand and Gravel
Sandstone and Shale
Carbonate (Limestone)
Crystalline

5. Sand and Gravel Aquifers
Along rivers and glaciated areas of northern PA
Shallow wells <100 ft
Large producing wells >100 gpm are common
soil
Sand and gravel

6. Sandstone and Shale Aquifers
Dominate much of state
Most wells are feet deep
Few large producing wells
Some fractures
sandstone
shale
sandstone

7. Limestone (Carbonate) Aquifers
Valleys of central and southern PA
Large yield in fractures
Very hard water (lots of calcium)
sinkhole
Limestone

8. Crystalline Aquifers Southeast PA Very dense rock, few fractures
Low yields (1 to 20 gpm)
Soft, acidic water
soil
Small fractures
Dense rock

9. Natural Groundwater Fluctuations
Fluctuations and drought susceptibility greater in shallow wells and springs
Ground
Surface
Spring recharge
Fall recharge
Summer
Deeper
Underground

10. Water stored in borehole
How Does a Well Work?
No pumping
“static water level”
150 gallons in a 6” well
with 100 feet of water
Water stored in borehole
Submersible
pump

11. When the Well is Pumped Drawdown Water flows into the well
from the surrounding rock
The “sustained yield” tells us how much water we can pump over a long time

12. Why do Wells Go Dry? Decreased recharge Drought Land use change
Increased pumping
Population growth
New users
Well structure
Natural aging
Pump

13. Monitoring Groundwater Levels

14. Springs
Occur where groundwater comes to the surface
Spring

15. Example of a Poorly Sealed Spring
Properly sealing a spring box helps to prevent contamination by surface water, insects, or animals
Example of a Poorly Sealed Spring

16. Components of Proper Spring Development
Collection system to concentrate flow
Reinforced and sealed concrete spring box
Easily accessible for
emptying and cleanout
Method of disinfection
(if necessary)

17. Spring Considerations
They are susceptible to drought
Most (> 75%) contain bacterial contamination and will need disinfection treatment (including roadside springs!)
They are more easily contaminated by surface activities – watch land uses around spring

18. A tank that collects and stores rainwater for household or other uses
What is a Cistern?
A tank that collects and stores rainwater for household or other uses
WHAT IS A CISTERN?
Cisterns date back to Greek & Roman civilizations
Still used today
used in areas of Pennsylvania where mining has contaminated ground and surface water
commonly used by farmers
to house

19. Facts About Cisterns
Cisterns date back to Greek & Roman civilizations
Still used today
used in areas of Pennsylvania where mining has contaminated ground and surface water
commonly used by farmers
Utilized in areas where all groundwater is heavily polluted – especially common in mining areas
Design based on $$, rainfall,
roof size, water needs
Minimum recommended size is 5,000 gallons
Locate above or below ground near the home

20. Cistern Maintenance All require treatment Disinfection
Corrosion prevention
Sediment removal / prevention
Only use approved materials on roof
Should be drained and cleaned periodically

21. Private Water Systems in this Region
# of homes served by private water systems
% of all homes served by public water
% of all homes served by private water system
County
1980
2000
Allegheny
15,216
9,136 98 2
Armstrong
13,240
14,242 44 56
Beaver
15,187
15,029 80 20
Butler
26,272
33,024 50
Clarion
8,241
12,505 42 58
Lawrence
19,290
19,858 77 23
Mercer
18,145
20,655 60 40
Venango
9865
14,917 54 46

22. Characteristics of Private Water Systems in this region
County
% drilled wells
% hand-dug wells
% springs or cisterns
Allegheny 81 7 12
Armstrong 69 9 22
Beaver 90 4 6
Butler 88
Clarion 55 33
Lawrence 5
Mercer 87
Venango 73 21