Battery driven portable pumps are small, cylindrical water pumps of varying diameters and capacities that are lowered into a well for purging and sampling. They are attached to wires (to be connected to a battery power source) and tubing (to allow the water to reach the surface for purging and sampling). They come in a variety of designs, sizes, capacities, and specifications. Manufacturers include Proactive, Whale and others; specification sheets are available from the manufacturer or environmental equipment suppliers. Advantages of this type of portable pump are the lower initial cost (typically about $100 for a small pump), ease of operation, and capability of very low flow to avoid problems with turbidity. However, they are limited in the effective sampling depth, and have much lower flow rates than standard electric pumps. With power boosters (to increase voltage from 12 to 24 volts), the sampling depth could be increased to around 200 feet. These pumps typically have an effective life of 400 to 600 hours of operation, so are not cost-effective with long term operation. Bladder pumps. The bladder in this type of pump is a balloon-like device inside the cylindrical pump housing, attached to an air line which extends from the bladder pump to the surface. The pump housing has two check valves and a water discharge tube that extends to the surface. When you lower a bladder pump into the well, water pressure causes the bladder to fill with water through one of the check valves. Compressed air or nitrogen is pumped through the air line into the annulus between the bladder and the pump housing, forcing the well water to exit the bladder through the other check valve and into the water discharge tubing. The process is repeated until the desired water volume is discharged. Advantages of this system are that extremely low flow rates may be obtained, to prevent turbidity or aeration, and to allow for very slow recharge rates in adverse hydrogeologic conditions. In addition, there is no limit on the depth, as the water is pushed to the surface. Disadvantages are the cost, which vary from $1000 on up, and the slow operation, which can be inefficient in larger wells where greater volume is desired for purging. Electric pumps. A third type of pump is the electric pump, made by several manufacturers, including Grundfos. This pump can deliver fairly low flow volumes (as low as 200 milliliters per minute), but has the option of higher flow rates if needed for purging. It also needs a generator or power source. Electric pumps are the most expensive, initially - a good electric pump setup, including generator, can cost upwards of $3000. However, these pumps have an effective working depth of 300 feet, and are sturdily built enough to last for many years. By Orrin Hall
Thursday, October 4, 2007
Sampling 101 – Pump or Bailer? - Part 2 of 3
SAMPLING PUMPS Pumps for field sampling are of several types; all are geared to purging and sampling ground water with a minimum of water turbulence and sample quality, and a maximum of operational ease. Advantages for the low flow portable pumps over bailers are that they reduce the amount of purge water removed from a well, which means less water to dispose of afterwards; low flow may also reduce the agitation of the formation water, therefore decreasing fluid turbulence and the potential for turbidity and aeration, which may increase inaccuracy and inconsistency of sample results. The optimum pumping rate should be equal to or less than the natural recovery rate of the well – this can be determined with continuous water-level measurements using an electronic water-level indicator. Disadvantages of low-flow pumps over bailers are the initial cost, the difficulty of cleaning (if the pump and tubing are not dedicated); and the possibility of sample water being subject to increases or decreases in air pressure during retrieval, which has a tendency to skew analytical results of volatiles. 
Battery driven portable pumps are small, cylindrical water pumps of varying diameters and capacities that are lowered into a well for purging and sampling. They are attached to wires (to be connected to a battery power source) and tubing (to allow the water to reach the surface for purging and sampling). They come in a variety of designs, sizes, capacities, and specifications. Manufacturers include Proactive, Whale and others; specification sheets are available from the manufacturer or environmental equipment suppliers. Advantages of this type of portable pump are the lower initial cost (typically about $100 for a small pump), ease of operation, and capability of very low flow to avoid problems with turbidity. However, they are limited in the effective sampling depth, and have much lower flow rates than standard electric pumps. With power boosters (to increase voltage from 12 to 24 volts), the sampling depth could be increased to around 200 feet. These pumps typically have an effective life of 400 to 600 hours of operation, so are not cost-effective with long term operation. Bladder pumps. The bladder in this type of pump is a balloon-like device inside the cylindrical pump housing, attached to an air line which extends from the bladder pump to the surface. The pump housing has two check valves and a water discharge tube that extends to the surface. When you lower a bladder pump into the well, water pressure causes the bladder to fill with water through one of the check valves. Compressed air or nitrogen is pumped through the air line into the annulus between the bladder and the pump housing, forcing the well water to exit the bladder through the other check valve and into the water discharge tubing. The process is repeated until the desired water volume is discharged. Advantages of this system are that extremely low flow rates may be obtained, to prevent turbidity or aeration, and to allow for very slow recharge rates in adverse hydrogeologic conditions. In addition, there is no limit on the depth, as the water is pushed to the surface. Disadvantages are the cost, which vary from $1000 on up, and the slow operation, which can be inefficient in larger wells where greater volume is desired for purging. Electric pumps. A third type of pump is the electric pump, made by several manufacturers, including Grundfos. This pump can deliver fairly low flow volumes (as low as 200 milliliters per minute), but has the option of higher flow rates if needed for purging. It also needs a generator or power source. Electric pumps are the most expensive, initially - a good electric pump setup, including generator, can cost upwards of $3000. However, these pumps have an effective working depth of 300 feet, and are sturdily built enough to last for many years. By Orrin Hall
Battery driven portable pumps are small, cylindrical water pumps of varying diameters and capacities that are lowered into a well for purging and sampling. They are attached to wires (to be connected to a battery power source) and tubing (to allow the water to reach the surface for purging and sampling). They come in a variety of designs, sizes, capacities, and specifications. Manufacturers include Proactive, Whale and others; specification sheets are available from the manufacturer or environmental equipment suppliers. Advantages of this type of portable pump are the lower initial cost (typically about $100 for a small pump), ease of operation, and capability of very low flow to avoid problems with turbidity. However, they are limited in the effective sampling depth, and have much lower flow rates than standard electric pumps. With power boosters (to increase voltage from 12 to 24 volts), the sampling depth could be increased to around 200 feet. These pumps typically have an effective life of 400 to 600 hours of operation, so are not cost-effective with long term operation. Bladder pumps. The bladder in this type of pump is a balloon-like device inside the cylindrical pump housing, attached to an air line which extends from the bladder pump to the surface. The pump housing has two check valves and a water discharge tube that extends to the surface. When you lower a bladder pump into the well, water pressure causes the bladder to fill with water through one of the check valves. Compressed air or nitrogen is pumped through the air line into the annulus between the bladder and the pump housing, forcing the well water to exit the bladder through the other check valve and into the water discharge tubing. The process is repeated until the desired water volume is discharged. Advantages of this system are that extremely low flow rates may be obtained, to prevent turbidity or aeration, and to allow for very slow recharge rates in adverse hydrogeologic conditions. In addition, there is no limit on the depth, as the water is pushed to the surface. Disadvantages are the cost, which vary from $1000 on up, and the slow operation, which can be inefficient in larger wells where greater volume is desired for purging. Electric pumps. A third type of pump is the electric pump, made by several manufacturers, including Grundfos. This pump can deliver fairly low flow volumes (as low as 200 milliliters per minute), but has the option of higher flow rates if needed for purging. It also needs a generator or power source. Electric pumps are the most expensive, initially - a good electric pump setup, including generator, can cost upwards of $3000. However, these pumps have an effective working depth of 300 feet, and are sturdily built enough to last for many years. By Orrin Hall
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