By David G. Hallauer
Jefferson County Extension Agriculture Agent
TMDL is a huge buzzword these days. What does it mean? How does it affect you and I?
TMDL stands for Total Maximum Daily Load. It is a measure of the maximum amount of pollution a water body can receive without violating water quality standards. These water quality standards were set up in accordance with the Clean Water Act of 1972. This act required states to set water quality standards for any body of water dependent upon its designated use for drinking water, recreation, wildlife or other uses. In addition, priorities had to be set on waters not meeting those standards. If one of these standards is exceeded, then a TMDL must be set for that body of water.
The setting of TMDLs will have quite an impact on residents of northeast Kansas and Jefferson County, as well. We are located in the Kansas Lower Republican River Basin. This basin has been identified as an immediate priority area for water quality improvements based on the TMDLs that have been set. Fortunately, very little of Jefferson County is included in the main focus areas. However, as continual stream monitoring continues and further TMDLs are set, other areas of Jefferson County may be affected. This will have an effect on not only those involved in crop and livestock production, but those in cities and the surrounding countryside, as well.
The total dissolved solids mentioned previously encompass a number of things. In Kansas, the No. 1 dissolved solid is sediment. This sediment comes from fields, construction sites and poorly managed grassland areas. At the current time, there are no clear standards set for sediment impaired streams and doing so is a difficult task.
Nutrients are the second high impairment. Fertilizer components, like phosphorous, adhere to soil and move with this soil when it is washed off yards and fields. In addition to fertilizers, pesticides also are considered an impairment. While we do have standards for many pesticides, there is still discussion as to what levels are safe in streams and rivers for use by the general public.
We focus much of our efforts now on pesticides, in particular atrazine, because we have a good idea about how to reduce these levels in bodies of water. Kansas State University has assembled best management practices for nutrients and pesticides used on cropland to better educate producers about practices they can follow to reduce runoff of these products in to streams and rivers. In addition, there is information about lawn fertilizer and pesticide use that will help even more in lowering levels of these impairments in our bodies of water.
The final impairment of concern is fecal material. Fecal material can come from any number of sources; cities, livestock feeding areas, sewer treatment facilities and many others. The standards set for fecal material are very low, and could require many changes in the way livestock, pet and human water products are handled.
The ultimate goal of the TMDL process is to determine water quality levels that need to be attained. After these levels are set, we can start work towards meeting the standards. As standards are met, bodies of water can be removed from the impaired list. If they are not, then further action will need to be taken , including regulatory measures, to ensure that our water is suitable for its intended purpose.
For more information about TMDLs and best management practices, contact the Extension staff.