Griffin has provided service and equipment to the construction dewatering and groundwater pumping market since 1934. For over 80 years Griffin has gained the respect of our customers by applying all the right solutions to their groundwater problems on projects both large and small. The key to Griffin’s success has been the combination of engineering staff, field personnel and experience. The wide variety of dewatering and pumping problems encountered by its customers has provided Griffin an opportunity to develop the necessary equipment and experience to solve most water handling problems.
The Deep Well System is also a versatile predrainage dewatering system which can pump high and low volumes of groundwater. This method is best suited to homogeneous aquifers that extend well below the bottom of the excavation. Deep well systems consist of one or more individual wells, each of which has its own submersible pump at the bottom of the well. Deep well systems are suitable for water-table or confined aquifers and will lower the water table 100 feet or more in a single lift without staging.
Griffin Dewatering offers effective and innovative turn-key solutions to groundwater control problems using Deep Wells. We offer a full professional service from initial design, drilling, supply and installation of pumping equipment together with all associated appurtenances.
- Ability to penetrate strata impervious to the jetting method of wellpoint systems
- Installation of up to 100 feet deep or more in a single stage
- Capable of pumping tens to thousands of gallons per minute per well
- Deep Wells can be effective when placed outside of the jobsite work area
Deep well dewatering systems are used when large volumes of groundwater must be pumped, highly permeable soils result in rapid recharging of the aquifer, and/or the depth of excavation excludes other dewatering methods.
The Well Point System is one of the most versatile of pre-drainage methods which can pump a few gallons per minute in fine sandy silts or many thousands of gallons per minute in coarse sands and gravels.
A well point system consists of a number of well points spaced along a trench or around an excavation site, all connected to a common header, which is attached to one or more wellpoint pumps.
Well point systems are most suitable in shallow aquifers where the water level needs to be lowered no more than 15 or 20 feet. Due to the vacuum limitation of the pump, excavations that are deeper will require multiple stages of well point systems.
When designing a well point system, it is necessary to give first consideration to the physical conditions of the site to be dewatered.
Things to consider include:
- The physical layout
- Adjacent areas
- Soil conditions
- The amount of water to be pumped
- Depth to imperviousness
To select the proper components of the well point system - the friction losses developed in the suction side system must be considered.
The Eductor System is especially suited for deep excavations and stratified soils. As many as 100 eductor wells are commonly activated by a single pumping station although this varies considerably on the volumes of water to be pumped and the lift required. The volumes of water which can be pumped by each system are generally low, typically less than 200 gpm..
The Eductor System is generally used in areas where the soils have a low permeability. It is especially well suited for deep excavations with stratified soils. The eductors are installed at relatively close spacing similar to the array in wellpoint systems, but require only a single stage to effect draw downs of up to 100 + feet.
- Not limited in vacuum limitation as in wellpoint systems
- Can lower water table as much as 100+ feet from the top of excavations
- Cost effective when compared to deep wells where close spacing is necessary because of stratification and/or low permeable soils
- Effective in soil stabilization by applying a high vacuum to fine grained soils.
- Low maintenance
In a typical Griffin eductor system, a series of eductor wells are installed and connected to two parallel headers. One header is a high-pressure supply line and the other header is low pressure return line. Both lines run to a central pump station which feeds water under pressure to eductors placed at the bottom of the wells.
The system uses a venturi to draw groundwater into the well screen and up to the surface. In the single pipe packer system the large diameter pipe forms the well casing and a smaller inner pipe forms the return line. Water is pumped under high pressure along the annulus between the two pipes and is forced through the nozzle and venturi. The groundwater is then recovered through the well and into the return pipe, resulting in a stabilizing effect in fine-grained soils.
Griffin Pumps provide the highest air-handling capacity on standard units in the market and are uniquely designed to address the needs encountered in dewatering, bypass, open pumping and hydraulic submersible pump applications. Griffin units are designed to give long, trouble-free service and perform continuously for extended periods with minimal attention and maintenance.
Griffin Pump & Equipment provides: