Science of Water : Concepts and Applications

40 The Science of Water: Concepts and Applications
drawdown). When conducting this test, if possible, always run the pump for the same length of time
and at the same pump rate.
WELL PUMPS
Pumps are used to move the water out of the well and deliver it to the storage tank/distribution system.
The type of pump chosen for use should provide optimum performance based on location and
operating conditions, required capacity, and total head.
Two types of pumps commonly installed in groundwater systems are lineshaft turbines and submersible
turbines. Regardless of the type of pump used, pumps are rated on the basis of the pumping
capacity expressed in gpm (e.g., 40 gal/min) and not on horsepower.
ROUTINE OPERATION AND RECORDKEEPING REQUIREMENTS
Ensuring the proper operation of a well requires close monitoring; wells should be visited regularly.
During routine monitoring visits, check for any unusual sounds in the pump, line, or valves,
and for any leaks. In addition, cycle valves routinely to ensure good working condition. Check
motors to make sure they are not overheating. Check the well pump to guard against short cycling.
Collect a water sample for a visual check for sediment. Also, check chlorine residual and treatment
equipment. Measure gallons on the installed meter for 1 min to obtain pump rate in gpm
(look for gradual trends or big changes). Check water level in the well at least monthly (maybe
more often in summer or during periods of low rainfall). Finally, from recorded meter readings,
determine gallons used and compare with the water consumed to determine possible distribution
system leaks.
Along with meter readings, other records must be accurately and consistently maintained for
water supply wells. This record keeping is absolutely imperative. The records (an important resource
for troubleshooting) can be useful when problems develop or helpful in identifying potential problems.
A properly operated and managed waterworks facility keeps the following records of well
operation.
WELL LOG
The well log provides documentation of what materials were found in the borehole and at what
depth. It also includes the depths at which water was found, the casing length and type, what type of
soils were found at which depth, testing procedure, well development techniques, and well production.
In general, the following items should be included in the well log:
1. Well location
2. Who drilled the well?
3. When the well was completed
4. Well class
5. Total depth to bedrock
6. Hole and casing size
7. Casing material and thickness
8. Screen size and locations
9. Grout depth and type
10. Yield and drawdown (test results)
11. Pump information (type, HP, capacity, intake depth, and model number)
12. Geology of the hole
13. A record of yield and drawdown data