Water Testing

Water Testing

Beginning in 2017, the Upper Republican Natural Resources District (URNRD) will sample more than 500 wells across the District to estimate the quality of our District’s water. While public water supplies are routinely monitored, water quality in private wells is left to the well owner or well water user to test. The URNRD’s water quality program assists well owners and users by sampling and testing private wells. Private well owners and users may acquire water test kits from the URNRD to determine the water quality in wells that the District does not check. 

Water Test Kits

The URNRD provides drinking water test kits to individuals in the District for domestic and livestock water wells at no charge. Water samples can be analyzed for multiple contaminants, ensuring the safety of your family's drinking water. Water test kits are available at the main URNRD office and should be returned to the office the same day, if possible, that water samples are taken. Water samples taken with the test kits should be returned to the URNRD office by 1 p.m. Monday-Wednesday.

For wells that are not already sampled by the District, the URNRD advises residents to take advantage of the free program and have their drinking water tested for contaminants, especially nitrate. High nitrate-nitrogen concentrations (> 10 milligrams per liter (mg/l) or >10 parts per million (ppm)) in drinking water can cause methemoglobinemia, or blue baby syndrome, in infants less than six months old. Pregnant women, those expecting to be pregnant, nursing women, and the elderly should also avoid water that contains a high nitrate concentration. Some locations in the District are also known to have high concentrations of arsenic and uranium. 

Some locations in the District are also known to have high concentrations of arsenic and uranium. If you have a concern about these contaminants, at a cost to the owner, a special kit from the URNRD can be obtained to test for those specific contaminants. 

URNRD Water Testing Program

Past Water Testing Program

The District's water quality sampling program began in 1974, and more sampling sites were added in 1980. In the winter, the same 77, mostly-unregistered, domestic and stock wells were sampled for nitrate each year.

In the summer, about 276 wells were sampled for nitrate each year. The same domestic and livestock wells were sampled as in the winter, and if a well had a nitrate concentration greater than 4 mg/l, then an additional 12 groundwater samples in a 3-mile radius were taken. These additional wells were mainly domestic and stock wells but they may also include irrigation wells. This normally added up to a little more than 200 wells (213 wells were sampled in 2015). In addition, 63 irrigation wells were sampled and tested in the summer for nitrate and the results submitted to the University of Nebraska-Lincoln for inclusion in their water quality database.

The new program is intended to provide more geographic uniformity of water testing in the district and better identify possible sources of water quality problems. The new water testing program will also provide potential solutions to water-quality problems.

Current Water Testing Program

The goals of the current water testing program are twofold – identify and reduce human health risk and improve the general health of the aquifer beneath the URNRD. Beginning in the summer of 2017, summer sampling will focus on the general “aquifer health” within the District. One hundred thirty-four irrigation wells will be sampled to estimate the average nitrate concentration throughout the district. The locations of the wells were chosen to obtain an accurate nitrate concentration throughout the District.  The results of the analyses determine the boundary designations of the different phase requirements for farm management practices within the District.  While most of the District has relatively good water quality, some areas have higher nitrate concentrations and in those areas the URNRD requires land owners and operators to follow farm management practices that will maintain or reduce nitrate concentrations in the ground water. 

The winter sampling focuses more on human health. There are about 380 registered domestic wells in the District, and the District will sample approximately 76 wells each year on a 5-year cycle, so all registered domestic wells will be sampled every 5 years. If a well has a nitrate-nitrogen concentration greater than 10 mg/l, then an URNRD representative will inspect the well’s construction information and site to determine the potential source of the high nitrate.

Unregistered wells may be sampled upon request, but the owner must first register the well. The sampling program is focused on nitrate, but if the owner has other water quality concerns, then the owner may request that the sample be tested for other water quality constituents.

Frequently Asked Questions

What is nitrate? Nitrogen is one of the primary nutrients necessary for plant growth.  The most common source of nitrogen used by plants is the nitrate ion, which is a combination of nitrogen and oxygen.  Nitrate is created from other nitrogen compounds (i.e. organic matter, nitrite, ammonium, and nitrogen gas) by bacteria in the soil. 

Why does nitrate in the ground water need to be monitored? When present in drinking water in high concentrations, nitrate can present a health risk. As previously-mentioned, the EPA water quality standard (10 mg/l of nitrate-nitrogen or 45 mg/l of nitrate) was set based on the causation of methemoglobinemia in infants and the elderly but studies have also shown a potential link between high nitrate concentrations and cancer, caused by the formation of nitrosamine compounds in the stomach.

Can high nitrate concentrations in water affect livestock? High nitrate-nitrogen concentrations can also cause methemoglobinemia in livestock, although livestock are less susceptible to methemoglobinemia than humans.  In general, water with a nitrate-nitrogen concentration in excess of 100 ppm is considered potentially harmful to livestock, although this limit is also dependent on the quantity of nitrate in feed and the age of the animal.

What causes high concentrations of nitrate in water? High nitrate concentrations in the ground water may occur naturally but usually they are a result of human influence. Nitrate is highly soluble and water entering the soil from precipitation or irrigation will carry nitrate not used by plants down to the ground water. Nitrate may enter the groundwater from non-point sources (sources that contribute nitrate over a broad area), such as agriculture fertilizers, or from point sources (sources that introduce nitrate at a single location), such as feedlots, septic systems, chemical spills, leaking chemical storage facilities, and improperly abandoned wells.

While infiltrating water conveys excess nitrate to the ground water tending to increase nitrate concentration over time, diffusion and dispersion can decrease nitrate concentration but they do not change the amount of nitrate. Nitrate entering the top of the aquifer will slowly mix with water deeper in the aquifer, tending to decrease nitrate concentration at the top of the aquifer but increasing the concentration at greater depths. Nitrate removed from the aquifer in the pumped water has no effect on nitrate concentration over time.  In general, the nitrate concentration in the District is gradually increasing over time (about 0.04 mg/l/year); although, in some locations it is decreasing. 

What do I do if my water has a high nitrate concentration? If your water exceeds the acceptable nitrate-nitrogen standard (10 mg/l), health risks can be reduced by using an alternate water supply (i.e. bottled water or water from a well with an acceptable nitrate concentration) or treating the water. Treatment options include distillation, reverse osmosis, or ion exchange, and a description of these techniques is provided below. 

Nitrate Treatment Options

Nitrate treatment options include distillation, reverse osmosis or ion exchange. Distillation heats the water to boiling, collects the steam, and condenses it by means of a coil. This process can remove almost 100% of the nitrate. Simply boiling water does not remove nitrate and will increase the nitrate concentration. Reverse osmosis applies pressure to the water and forces it through a semipermeable membrane that filters out the nitrate. Typically, this removes about 85% to 95% of the nitrate. Ion exchange uses special resins that exchange chloride ions for sulfate and nitrate ions as the water passes through the resins, similar to a water softener, and can remove about 90% of the nitrate. Of these methods, reverse osmosis and ion exchange are the most common methods used for residences and will be the only method discussed below. Table 1 provides a comparison between reverse osmosis and ion exchange treatment systems.

The nitrate treatment systems also come in Point-of-Entry (POE) and Point-of-Use (POU) systems. POE systems treat water before it enters the home so all of the home’s water will be treated. Their cost ranges between $1,000 and $5,000 as of 2018.  POU systems treat water where it is used.  For instance, a POU system could be hooked up under the kitchen sink and only treat the water that comes out of that faucet.  POU systems cost generally varies between $100 and $1,000.

Table 1: Nitrate Treatment Option Comparison

 

Ion Exchange

Reverse Osmosis

Pretreatment Required

Sometimes

Sometimes

Removal Efficiency

90%

85% to 95%

Raw Water Issues

Resin sensitive to iron, manganese, sulfate, organic matter, and TDS

Process sensitive to iron, manganese, sulfate, organic matter, TDS, and turbidity

Post Treatment

pH adjustment may be required

Low TDS output water may require water quality adjustment

Waste Disposal

Salt Brine and rinse water

Concentrate

Process Start-up Time

Minutes

Minutes

Advantages

  • Ease of operation
  • Relatively reliable
  • Effective 
  • Ease of operation
  • Relatively reliable
  • Effective

Disadvantages

  • Requires frequent monitoring
  • Can be expensive to install and maintain
  • Salt brine disposal
  • Requires storing salt
  • Changes in finished water pH
  • Potential for high concentrations of nitrate due to “dumping” nitrate from column
  • Requires frequent monitoring
  • Can be expensive to install and maintain
  • Concentrate disposal
  • Reduces minerals in finished water