Mississippi

An Animal Waste Irrigation Project in Mississippi -
Saving Farmers Money

Mississippi's Soil and Water Conservation Commission has initiated a demonstration projectthat will ultimately change the way lagoonsand other animal waste facilities are managed. A relatively simple description explains the activity: farm workers remove (pump) solids from improperly functioning animal waste lagoons and apply them to the land with a traveling gun irrigation system.

Animal waste is a contributing factorto the high level of nitrogen, phosphorus,and fecal coliform found in some Mississippi streams. However, on land, the fecal coliform die and the nitrogen and phosphorus becomea rich source of natural fertilizer. Production values increase when animal wastes are recycled, and the water stays cleaner.

Improperly functioning lagoons?

Animal waste lagoons stop functioning properly if they are being misused, that is, if they are too small; or if they are not properly maintained. Suppose one has an older lagoon, one built for 50 head of cattle. If the herd increased to 100 head, the old lagoon will fill up twice as fast. Further, removing the solids that accumulate in any lagoon is a standard operating procedure that should be performed regularly.

This project, which was funded through a 319 program grant from EPA, began in the Amite, Pike, and Walthall County Soil and Water Conservation Districts in southwestern Mississippi. Those districts were selected for the first demonstrations to help remedy water quality problems in the Tangipahoa River. Once the irrigation system was demonstrated in this area, other districts began to serve as demonstration sites.

Nutrient management plans

Demonstration sites must have a suitable amount of pastureland or cropland near the lagoons being pumped out. Landowners participating in the demonstration (or choosing this option as a best management practice) are required to consult with the Natural Resources Conservation Service. An approved animal waste management plan should be developed for each lagoon system.

The waste management plan may also include a nutrient management plan. Farmers must know the nutrient content in their lagoon, the amount of nutrients already available in soil resources, and plant nutrient needs before they can determine how much waste can be properly applied.

An economic and environmental success

During the entire time period of this project, a total of 12 lagoon systems were pumped out. Of these, 10 were dairy lagoon systems, one was a swine lagoon system, and the other a poultry lagoon system. The total amount of land used for the applications included 192 acres of cropland and 206 acres of pastureland.

The total volume of lagoon effluent irrigated onto these acres contained 72,402 pounds of nitrogen, 34,911 pounds of phosphorus, and 82,715 pounds of potassium. The dollar value of those nutrients — that is, the money landowners saved in fertilizer costs — was $19,548.54 for nitrogen, $6,633.09 for phosphorus and $9,925.80 for potassium.

The landowners who participated in this demonstration project were pleased with the outcome. They knew that a positive impact was being made on water quality through this system and agreed with the Mississippi Soil and Water Commission that the demonstration contained at least the following benefits:

• The irrigation system helps alleviate lagoon overflow problems, thus preventing water quality problems in the demonstration areas.
  
• The project shows that more expensive and time-consuming equipment is not necessary for the adoption of this lagoon management practice. Tank trucks and tractors, which cause soil erosion and compaction, can be eliminated.
  
• Production costs are significantly lower when nutrients are recycled to crop and pasture systems. The alternative practice, commercially formulated fertilizers, is more expensive.

This system has now been transferred to the Mississippi Soil and Water Conservation Commission who will continue to demonstrate its benefits, especially in Mississippi's priority watersheds. Having received numerous requests for use of the system, the Commission applied for, and received, an additional grant from the Tennessee Valley Authority (TVA) Land and Water 201 program to purchase an additional system. That system is now in use in the 32 TVA counties in Mississippi.

Lake Hazle Project Takes on Urban Runoff:
Expects Return of Beneficial Uses

Lake Hazle, a 22-acre public lake in Hazlehurst, Mississippi (about 40 miles south of Jackson), is used for fishing, wildlife, and aesthetic quality. Nearly one-quarter of its 400-acre drainage area has been developed for commercial or residential use. Approximately 50 acres of the surrounding land contribute sediment runoff. Service stations, auto repair shops, streets, highways, and parking lots collect oil and grease, and highway construction and commercial developments are another major source of contaminated runoff and sediment. The impacts from these nonpoint sources of pollution are keeping Lake Hazle from meeting its designated uses.

The purpose of the Lake Hazle Project was to identify and correct the nonpoint sources of urban runoff, thereby restoring the recreational values and aquatic life resources of the lake to their full potential. EPA provided 319 funding for the project. Several other state, federal, and local governmental agencies were cooperating partners, including the Mississippi Soil and Water Conservation Commission; Copiah County Soil and Water Conservation District; the USDA Natural Resources Conservation Service; the Department of Environmental Quality, Office of Pollution Control; the City of Hazlehurst; and the Southwest Resource Conservation Development Office.

In 1990, EPA's Region 4 provided guidance on the proposed Lake Hazle monitoring plan. The Water Quality Assessment Branch of the state Department of Environmental Quality implemented the monitoring plan to document improvements to water quality from the installation of best management practices in the Lake Hazle watershed.

Section 319 grant funds funded up to 60 percent of the best management practices (BMPs). Nine BMPs were installed to treat runoff from 233 acres. Of the nine practices, six were critical area plantings; one, a grade stabilization structure; and two were water and sediment control wet detention basins. As a result of these activities, 2,238 tons of soil annually are retained on properties adjacent to the lake. Although water quality has improved, additional practices are needed to bring Lake Hazle to its fullest potential.

Awareness and water quality increase

Comparisons of monitoring samples taken before and after the practices were installed show a dramatic decrease in suspended solids following the installation of stormwater controls. The critical area plantings and other practices had a similarly dramatic effect, as did the BMPs installed to manage stormwater sediment. The depth of the euphotic zone (water clarity) increased 72 percent, thereby taking sunlight to greater depths and increasing photosynthesis in the lake. Other water quality parameters were also monitored:

• Dissolved oxygen and temperature data are less conclusive, but indicate that dissolved oxygen did increase, though slightly, at both middle and bottom depths during the post-BMP period.
  
• Tests indicate a reduction in nitrate-nitrogen concentration greater than 61 percent. The reduction of total nitrogen in stormwater runoff had a positive effect on nitrogen within the lake. Once BMPs were introduced around the lake, the in-lake total nitrogen concentration fell by 54 percent.
  
• Stormwater runoff concentrations of phosphorus declined by 50 percent. Lake samples indicate that the combined project activities reduced phosphorus loading to the lake by 34 percent.
  
• Pre-BMP stormwater monitoring showed a very high number of fecal coliform (bacteria) colonies; post-BMP levels fell by 84 percent.

Lake Hazle's water quality has clearly improved since the implementation of BMPs throughout the watershed. However, it is still too early to determine the long-term effects of these activities. As project activities continue and lake users become more aware of how nonpoint sources affect water quality, it is possible to anticipate that Lake Hazle will be restored sufficiently to support its original designated uses.

Mississippi Demonstrates Dead Chicken Composting:
A Water-Quality Safe Disposal Method

At the time this project began, southcentral Mississippi was bracing for a rapid expansion of the poultry producing industry. It was widely predicted that the poultry population in a six-county area would increase to approximately seven million birds. In fact, in 1993, 62 growers handled 7 million birds and by 1997, 150 growers reported a census of 16.2 million birds. In an industry this large, the disposal of dead birds must be carefully managed to avoid potential threats to surface and groundwater resources.

Alternative methods

Traditionally, dead birds have been disposed in burial pits or incinerated. Unapproved methods were sometimes discovered, such as exposing the carcasses or dumping them in streams or roadside ditches. But even the approved methods carry some risk of water contamination that adds to the cost of production. Arkansas, another major poultry-producing state, has recently prohibited the use of pits for dead bird disposal, and other states are likely to take this action in the near future. The Arkansas ban tells the story: often the carcasses decay only partially and leachate from the pit poses a danger to surface and groundwater.

In Mississippi's case, several agencies worked with local soil and water conservation districts to educate and advise area producers about the composting project, then provided technical assistance to those who cooperated. The original project plan called for one composter to be constructed in each district included in the demonstration, but the project was so well received in two conservation districts that an additional composter was constructed with cooperators electing to divide the cost-share funds among themselves.

Following construction, workshops were held in each of the participating conservation districts to give participants an opportunity to relate their experiences. Local producers who had not participated and the general public were also invited to learn more about the use of composters to protect water quality. The Department of Environmental Quality expects more composting facilities to be constructed if producers can obtain funds to cover the cost of construction.

Benefits that distinguish composting from other methods

Approximately 194,400 birds per year will be disposed of by composting in a manner that reduces the chance of groundwater contamination. And area farmers are realizing an additional benefit. Many are saving up to $25 per ton by using the composted material as fertilizer, thereby reducing their purchase of and dependence on commercial fertilizers for land applications. When composting is combined with other practices such as soil testing and nutrient management planning, it reduces the risk of nutrient enrichment to nearby surface waters.

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