Water numeric nutrient criteria: what, why and 4Rs

decrease font size  Resize text   increase font size       Printer-friendly version of this article Printer-friendly version of this article

State water quality agencies have the major responsibility of ensuring the protection of water resources from nutrient (N and/or P) pollution.

For decades, lake, stream, and river water quality nutrient levels have been periodically monitored by either state agencies or federal agencies.

Historically, most states have relied on narrative nutrient criteria that stipulate that designated uses of water resources shall not be impaired by nutrients.

Since about 2000, the U.S. EPA has emphasized the need for more robust numeric nutrient criteria by states, based on sampling of reference waters and human-impacted waters. The EPA has advocated use of overlapping frequency distributions of nutrient levels from least-impacted reference streams/rivers and monitored streams/rivers, in selecting numeric nutrient criteria.

Last year, in its 2013 release of the 2008-2009 National Rivers and Streams Assessment Report on water quality (http://water.epa.gov/type/watersheds/monitoring/aquaticsurvey_index.cfm), the EPA used a more narrowed statistical approach than in the past, in interpreting stream/river quality conditions. Overall, the U.S. EPA found that 55% of the monitored rivers and streams were in poor biological condition. Compared to the 2004 EPA wadeable stream assessment, 7% fewer stream miles were in good biological condition and 19% fewer stream miles were in good condition for P.

The good news was that 9% more stream miles were in good condition for N, 17% more stream miles were in good condition for in-stream fish habitat, and 12% more stream miles were in good condition, as measured by riparian disturbance.

Currently, seven states have statewide or partial N numeric criteria for rivers/streams; while 11 have state-wide or partial P numeric criteria for rivers/streams. More states are making progress (http://cfpub.epa.gov/wqsits/nnc-development/), and the number of states with statewide or partial numeric criteria may double by 2016. According to a 2013 paper published in the Journal of Environmental Quality (https://www.agronomy.org/publications/jeq/pdfs/42/4/1002?search-result=1), among the several states with site-specific nutrient criteria for streams and rivers, only Wisconsin and Florida have statewide criteria which are well-supported by peer-reviewed and technical papers documenting the process of criteria development. A number of states have developed new nutrient loss reduction strategies. Several state strategies are designed to primarily encourage agriculture, and other nonpoint or diffuse sources of nutrient loss from land to water resources, to become more aggressive with their best management practice implementation and mitigation actions.

The 12 states adjacent to the Mississippi River are under greater pressures to do even more to reduce the losses of N and P that get transported downstream to the Gulf of Mexico, and which aggravate the early summer development of low dissolved oxygen conditions (hypoxia) in the northern Gulf of Mexico.

Each of those 12 states is developing, or has developed, a nutrient loss reduction strategy to further its commitment to improved and protected water quality throughout the Mississippi River Basin and the northern Gulf of Mexico.

More agricultural losses of N and P from nonpoint (diffuse) sources can be curbed, through more timely and wise implementation of 4R (right source at the right rate, time, and place) nutrient management practices.

Those 4R practices will be most effective when skillfully combined with in-field and edge-of-field soil and water conservation practices. There is no time like the present to keep more of our applied nutrients in fields and out of water resources.

How will you be adjusting your 4R nutrient management and soil and water conservation plans to be part of the winning water quality solution?

Prev 1 2 Next All

Buyers Guide

Doyle Equipment Manufacturing Co.
Doyle Equipment Manufacturing prides themselves as being “The King of the Rotary’s” with their Direct Drive Rotary Blend Systems. With numerous setup possibilities and sizes, ranging from a  more...
A.J. Sackett Sons & Company
Sackett Blend Towers feature the H.I.M, High Intensity Mixer, the next generation of blending and coating technology which supports Precision Fertilizer Blending®. Its unique design allows  more...
R&R Manufacturing Inc.
The R&R Minuteman Blend System is the original proven performer. Fast, precise blending with a compact foot print. Significantly lower horsepower requirement. Low inload height with large  more...
Junge Control Inc.
Junge Control Inc. creates state-of-the-art product blending and measuring solutions that allow you to totally maximize operating efficiency with amazing accuracy and repeatability, superior  more...
Yargus Manufacturing
The flagship blending system for the Layco product line is the fully automated Layco DW System™. The advanced technology of the Layco DW (Declining Weight) system results in a blending  more...
Yargus Manufacturing
The LAYCOTE™ Automated Coating System provides a new level of coating accuracy for a stand-alone coating system or for coating (impregnating) in an automated blending system. The unique  more...
John Deere
The DN345 Drawn Dry Spreader can carry more than 12 tons of fertilizer and 17.5 tons of lime. Designed to operate at field speeds up to 20 MPH with full loads and the G4 spreader uniformly  more...
Force Unlimited
The Pro-Force is a multi-purpose spreader with a wider apron and steeper sides. Our Pro-Force has the most aggressive 30” spinner on the market, and is capable of spreading higher rates of  more...
BBI Spreaders
MagnaSpread 2 & MagnaSpread 3 — With BBI’s patented multi-bin technology, these spreaders operate multiple hoppers guided by independent, variable-rate technology. These models are built on  more...

Comments (0) Leave a comment 

e-Mail (required)


characters left


YOUR BEST HARVEST IS NOW WITHIN REACH J&M introduces their patented line of X-tended Reach grain carts, featuring a frontfolding single ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form