Groundwater Management Area
The Lower Elkhorn NRD has established a groundwater management area to improve and protect groundwater quality in the district.
"This will be accomplished by minimizing the impact of agricultural chemicals on groundwater by encouraging, and in some cases requiring, the use of wise management practices," says Rick Wozniak, water conservation specialist.
The Lower Elkhorn NRD has followed the lead of other NRDs in the state that have established groundwater management areas in the development of the various components of the project.
One of the major components of the groundwater management area is a phased approach of regulation that requires varying degrees of reporting and best management practice use.
According to Wozniak, each phase has a unique set of requirements for farmers.
They are as follows:
Phase 1 -- Areas that are not designated as either Phase 2 or Phase 3.
Phase 2 -- Areas that have from 50% to 90% of the Maximum Contaminant Level for a contaminant (5 to 9 ppm of nitrate-nitrogen), or are vulnerable to groundwater contamination, or have vadose zone contamination that indicates a potential for groundwater contamination, or are in the recharge areas for public supply wells, or are areas with similar soil and land use conditions as an existing Phase 2 or 3 area. Phase 2 areas must be a minimum of 10 square miles in size.
Phase 3 -- Areas with greater than 90% of the Maximum Contaminant Level for a contaminant (9 ppm of nitrate-nitrogen), or are vulnerable to groundwater contamination, or have vadose zone contamination that indicates a potential for groundwater contamination, or are in the recharge areas for public supply wells, or are areas with similar soil and land use conditions as an existing Phase 3 area. Phase 3 areas must be a minimum of 10 square miles in size.
Phase 1 Controls
- Persons installing new or replacement wells with a capacity greater than 50 gallons per minute must obtain a permit from the NRD.
- The district will encourage operators to attend certification classes for fertilizer and irrigation water management, to perform deep soil testing for residual nutrients, to test irrigation water for nutrients and to submit an annual report of fertilizer application to the district.
- The district will also encourage operators to use nitrification inhibitors or split application of nitrogen fertilizers and to not apply nitrogen fertilizer in the fall or winter.
Phase 2 Controls
- All Phase 1 requirements
- All operators using commercial or organic fertilizers must be certified by the district.
- Irrigation water must be tested for nitrate-nitrogen.
- Soil must be tested for residual nitrogen content to a 2 foot depth each year in which a non-legume, annual row crow will be planted for at least the second consecutive year (for example, a corn-on-corn rotation).
- All operators applying fertilizer must submit a report to the district every year (due December 31st).
Phase 3 Controls
- All Phase 1 & 2 requirements
- Operators are required to meter volume of irrigation wells. (See list of approved flow meters)
- Irrigation scheduling is required.
Recommended Management Measures
- Use of flow meters on wells (see list of approved flow meters)
- Eliminate fall and/or winter fertilizer application or include the use of a nitrification inhibitor.
- Spring applications of commercial fertilizer should be split (preplant and sidedress) or include a nitrification inhibitor.
- Analyze contaminant sources such as manure
- Prepare and implement a plan for manure disposal
Reasoning for Management Phases
"The use of several phases allows the district to adapt different requirements to assorted conditions," Wozniak says. "The requirements for an area may change, either becoming more strict when conditions worsen or lenient when conditions improve," Wozniak added.
The designated boundaries for the phases of the groundwater management area may follow either natural or political boundaries. The boundaries may be drawn around existing problem areas or potentially vulnerable areas.
Wozniak says that determining the mechanism for boundary setting is a very important part of establishing a groundwater management area.
The combination of controls required in each phase should address the problems associated with that phase of the project and will be voted on by the board.
Public comments on the groundwater management plan are welcome at any time. Please contact the district if you would like additional information on this issue or would like a district representative to speak to your group.