Groundwater Quality Rules & Regulations
Since 1985, the Lower Platte North NRD has been monitoring nitrate levels across the district. In certain areas of the district, nitrate levels have already exceeded the health standard of 10 parts per million, and in other areas contamination seems to be on the rise. This was the major impetus for the creation of the Ground Water Management Area in 1997.
Excessive nitrates in drinking water, often linked to irrigated row crop production, can endanger pregnant women and infants by interfering with the oxygen-carrying capacity of the blood. Some studies have also linked excessive nitrate consumption with increased incidence of gastrointestinal cancer, but these reports remain unconfirmed.
To help correct the rising nitrate levels in our groundwater, the NRD has set requirements for producers who use fertilizer in the district.
Currently, the majority of the Management Area is in Phase I, which emphasizes education about fertilizer use.
Phase I Requirements
- Operators using any type of fertilizer must become certified every 4 years.
- At least once every 4 years, a groundwater analysis for nitrate-nitrogen must be made and reported to the NRD by Dec. 31 for all irrigation, municipal, and industrial wells.
- Permits are required for all new wells with a capacity greater than 50 gallons per minute.
- The amount of organic fertilizer (liquid or dried manure, sludge, or composted organic waste) allowed per acre per year will be based on the method of collection and storage, land application method, type of crops or cover crop, soil types, landscape features, source of manure, and previous manure application rates.
- Fall application of commercial nitrogen fertilizer is prohibited on non-sandy soils before November 1.
- Fall and winter application of commercial nitrogen fertilizer is prohibited on sandy soils until March 1.
Encouraged but not required:
- Soil samples taken in the root zone (to a depth of 3 feet) and reported to the NRD by Dec. 31 each year.
- Fertilizer application report (both commercial and organic fertilizers) made to NRD by Dec. 31 each year.
Nitrate levels across the district are periodically reevaluated, and as a result some areas may enter more restrictive phases, with additional requirements for fertilizer use.
Additional Requirements for Phase II
(Nitrate Nitrogen Levels of 8-10 Parts Per Million After Jan. 1, 2001)
- Groundwater analyses, deep soil samples and fertilizer application reports will become annual requirements.
- Commercial nitrogen fertilizer will only be permitted on non-sandy soils from Nov. 1 to March 1 if an approved inhibitor is used at recommended rates.
- Operators applying commercial fertilizer from Nov. 1 to March 1 must furnish certification from their dealer that an approved inhibitor was used as recommended.
- Water applications must be monitored to allow for better management of fertilizer application and to control leaching of nitrate (phased in over 6 years).
- The amount of organic fertilizer (liquid or dried manure, sludge, or composted organic waste) allowed per acre per year will be based on the method of collection and storage, land application method, types of crops or cover crop, soil types, landscape features, source of manure and previous manure application rates. The amount and timing of applications must be adjusted to the nitrate concentration in the soil profile and groundwater content. Application will be allowed on frozen soils on a site-by-site basis only.
Additional Requirements for Phase III
(Nitrate Nitrogen Levels Exceeding 10 Parts Per Million After Jan. 1, 2001)
- Application of commercial nitrogen fertilizer will be prohibited in fall and winter on all soils until after March 1. Spring applications of commercial nitrogen fertilizer will require split application (pre-plant and sidedress) or the use of an approved inhibitor applied as recommended. (Use of an approved inhibitor is also required on split applications where 50% or more is applied as pre-plant.)
- If 50% or more of commercial nitrogen fertilizer is applied at pre-plant, then operators are required to furnish certification from their dealer that an inhibitor was used at recommended rates.
- Water applications must be monitored to allow for better management of fertilizer application and to control leaching of nitrate (phased in over 6 years).
More Information
If you have questions or would like more information about the GWMA, please contact Water Resources Manager Larry Angle.