Groundwater dewatering wells are used to lower the water table for construction activities. The following is required for dewatering wells:
- Private Well Construction Permit
- Water Use and Allocation permit or minor non-recurring use permit
- General Permit #9
- A DNR certified well driller must be onsite at all times that well services are being performed.
Trench dewatering has the same requirements as groundwater dewatering wells, except they do not require a private well construction permit.
Monitoring Wells - Iowa DNR private well construction permits are always required for monitoring wells except for wells installed as part of a Iowa DNR requirement for an underground storage tank site (UST), leaking underground storage tank site (LUST), contaminated site, or landfill site. All monitoring well construction must be performed under the direct supervision of an Iowa DNR Certified Well Contractor who is onsite and in direct control of the well services being provided. When any monitoring well is no longer needed, it must be properly plugged with bentonite products or neat cement, the casings removed to a depth of four feet below surface grade, and one Iowa DNR Form 542-1226 filed with the department for each monitoring well plugged.
Geotechnical Investigation Boreholes - Iowa DNR private well construction permit is not required for any borings for geotechnical investigations, nor is a certified driller. A well construction permit and Iowa DNR Well Contractor Certification is required if your geotechnical investigation includes placing well casings or screens in any boreholes to monitor or collect groundwater samples. Any investigation boreholes that are positioned in areas that will not be immediately excavated must be properly plugged with bentonite products or neat cement.
Geoprobe® Style Boreholes - Iowa DNR private well construction permits are not required for Geoprobe® style boreholes as long as temporary or permanent well casing is not installed in the borehole. Example, when sampling of groundwater through the probe tip without using any casing. If your boring(s) will place any casing in the ground, you need to obtain well construction permits before any probe work is started and have a Iowa DNR Certified Well Contractor on-site during the installation. All probe holes must be properly plugged with bentonite products or neat cement as soon as the sampling work is completed.
Cathodic Protection Wells - Iowa DNR private well construction permits are not required for cathodic protection wells. Cathodic protection wells are common and installed to protect metallic objects in direct contact with the ground from electrolytic corrosion. Objects like pipelines that carry petroleum, natural gas, and water, and their related storage facilities; power lines; telephone cables; and switchyards. In addition, cathodic protection wells are sometimes used to control electrolytic corrosion in large water supply wells. Even though construction permits are not required for cathodic installations, the installation contractor is still responsible to ensure that each borehole is constructed using the best industry standards - including bentonite products to seal between potential aquifers and the upper borehole, and the use of safe materials that will not contaminate drinking water supplies.