Liquid-Solid Separation and
Commingling Research Project

Phyllis Steinke and Jim Phillips
Logan and Shelby Soil and Water Conservation Districts

A byproduct of livestock production, manure, has long been know for its fertilizer and organic material value. Also known is its associated concerns: odor, hauling and application, storage needs, and societies views of this natural, organic nutrient. New and innovative techniques on managing manure are the byproducts produced from these concerns.

The main objective of the project was to aid the livestock producer with a way to improve the management of the volume of the manure produced, thus reducing the potential for the occurrence of non point source pollution. As preparation for this objective progressed, other concerns surfaced, which led to the commingling proposition.

The project involves two watersheds, which have heavy livestock / agricultural production and recreational lake use. Due to past agricultural practices, both lakes have lost a great percentage (approximately 30%) of their volume due to sedimentation. Dredging the sediment is a very expensive program for each watershed. One of the high costs of dredging involves the acquisition of land to receive dredge spoil. By enriching the dredge spoil with organic material separated from livestock manure, an attractive product will be produced and recycled back to the watersheds as a soil amendment. This will reduce the need for new dredge spoil sites, and thereby, reduce the cost of dredging.

By separating out the solids from the manure, the livestock producer will enjoy many benefits, some such as: increased storage volume, odor reduction, less solids in the liquid which enables the liquid to rapidly penetrate the soil when spread and does not cap the soil surface with solids, and can irrigate the liquid in growing crops without damage.

Analysis of all components of the project is on going. The nursery / landscape operators who utilize the product will record the benefits and values. The livestock producer will evaluate odor reduction, percent of increase in storage volume, application of the liquid to standing crops (e.g.; variable rates, timeliness of application, and crop response).

The ultimate objective is to improve manure management, which will benefit the livestock producer, and to produce an environmentally friendly, value added product that can be marketed wholesale or retail for various soil improvement needs such as: critical area seedings, horticultural and landscaping needs, and as a general organic soil amendment, which will benefit the watersheds and all their inhabitants.

This project was made possible by partnering with a local swine producer, a local contractor who specializes in top soil production, the Logan and Shelby Soil and Water Conservation Districts, the Indian Lake Watershed Project, the Lake Loramie State Park, Ohio Department of Natural Resources-Division of Soil and Water, Ohio State University, U.S. Army Corp of Engineers, and Ohio Environmental Protection Agency.

The Ohio Department of Natural Resources, Division of Soil and Water Conservation, Pollution Abatement and Land Treatment Section, (ODNR-DSWC-PALT), is very dedicated to providing opportunities for the Soil and Water Conservation Districts of Ohio and their partners to demonstrate new technology and methods to educate producers about manure utilization. The ODNR-DSWC-PALT, requested Manure Nutrient Management Innovative Demonstration Proposals, which if accepted, would obtain grant funds to aid in the execution of the project. This paper is a discussion of an innovative demonstration project, which is partially funded through ODNR, with in-kind services from several agencies, a private contractor, private business, vocational schools, and the livestock producer himself.

Within the last two years, not only the number of confined swine feeding operations has dramatically increased in both Shelby and Logan Counties in Ohio, but also the size of existing operations. Most of these operations have under-the-building, deep pit, manure storage with approximately 3-6 months storage. Some of these operations are also installing along with the pits holding ponds and/or lagoons for storage or treatment of the manure until application to land is feasible.

The guidelines for acres required for manure application for these operations usually exceeds the acres available to the producers, which sometimes leads to over application of manure to the land. Initially, this was the thrust for the project, increasing the present storage volume, without construction of additional storage. As initial work on the project began, several other resource concerns surfaced.

The Delta RS - 1 Separator System had been used at several locations for demonstration. A local swine producer was interested so arrangements were made for a demonstration to be held at his farming operation. Several objectives were discussed, which brought about the commingling concept. The livestock producer was basically satisfied that the separated liquid would supply all the nutrients needed for his operation, with some of the solids acting as a starter for composting mortality. So now, what would he do with all that separated solid manure? Along with the increase in livestock / agricultural production, there is also an increase in housing development around both lakes in both counties. With housing comes landscaping which needs topsoil. Because both SWCD's work with their respective State Parks, primarily with water quality concerns, the topic of dredge material kept surfacing.

Knowledge of a local contractor who was starting a business of topsoil production was the connection needed for a market for the separated solids. Mixing the separated solids with the dredge material could produce an organic fertilizer and soil conditioner which, could be a valuable source of humus for gardens, greenhouses, critical area seedings, and maybe even a top soil for lawns. Also, the recycling of the dredge material by commingling with the separated solids could become a long term management alternative for the dredge material that is removed from both the State Parks. The commingling project will also compliment the lawn care education effort for the residential population around the lakes. Lake residents will have a soil amendment available which recycles two Nonpoint source pollutants, sediment and manure solids. At this point, the material produced will be considered a general soil amendment.

The contractor has a mixing/sorting/grinding machine, dump trucks, loaders, and a under-roof storage area for the finished product. Terms for hauling of the dredge material from the lakes and the separated solids from the farm is still being worked out. Dollar values for the separated solids, dredge material, and finished product are also being researched and negotiated.

The livestock producer bought the separator early summer of 1997. The producer has already seen increased storage capacity of approximately 3 - 4 weeks (15%), giving him a larger window of opportunity for proper timing of manure application. He did apply manure in October, using injection instead of surface application, which has proven to reduce some of the odor. But, he was really surprised when one of his closest neighbors called to ask when manure was going to be spread. The neighbor was going to be hosting a special event. The neighbor was "stunned" when he learned the manure had already been applied.

Samples of the soil amendment, separated solids and dredge material have been displayed at a couple of field days. Responses from the general public who viewed the product are surprising. Some thought the soil amendment was compost that had been bought from the store. Some people thought it smelled like silage. Several people wanted samples or a "few pick-up loads" to take home and just experiment with. All thought the project was worth the effort, work, and time that was being put into it. Imagine that, city folk wanting to bring home pig manure to plant their flowers in! A very promising attitude.

There has been some initial testing for nutrient content in the liquid and solids. The producers biggest concern for manure application is the Phosphorus (P) content. According to NRCS (National Resource Conservation Service) Standards and Specifications, P is the limiting factor in manure application. A livestock producer usually has sufficient or excess P levels to grow crops. The initial tests show that 60% of the P205 stays with the solids. The separated liquid analysis has tested for 14% N, which is better than expected. This liquid will be used on test plots as a sidedress for corn. This will be done with a soil doctor or a 28% injector. This is a very important economic benefit for the farmer. Again, an increase of 15% storage capacity, greatly reducing the amount of commercial bought N, reduced application time, less odor (mostly due to faster absorption by the soil due to decreased solids), the separated solids are a byproduct that can be marketed, which would also help recoup the cost of the equipment, and the farmer is turning a liability into an asset, avoiding both the dangers of nuisance suits from pollution and the costs of lagoons and disposal. Also, a portable unit could be co-owned by hog producers or co-ops therefore reducing the costs of owning the equipment.

Past tests of the dredge material have been done to check for heavy metals such as polychlorinated biphenyl's (PCBs). But, industry is low around the lakes, and the tests revealed that with concentrations being very minute. Current and future testing will monitor the levels.

The project is basically just getting off the ground. The soil amendment will not be marketed at this time for its nutrient content but, a general analysis will be made available for information. Depending on the end use of the product will determine how extensive the nutrient analysis needs to be. For example, there are general parameters within which grass stands can be established. The success in establishing landscapes is dependent on knowing the soil on site, the species of plants to be planted and which organic amendment to use. Although the soil admendment will add both organic matter and nutrients essential for plant growth, there are times when the nutrient and pH levels of the soil may be adequate or may be excessive and organic amendments such as peat moss and/or pine fines may be a better choice (Gouin, 1977). Because of this, continuous testing of the final product will need to be ongoing.

Contact has been made with a vocational schools horticultural department.

As a research project, students can provide "in-kind" services such as: charting ratios of blends, seed germination, and plant growth. Leachate and tissue tests from the plants will reveal if any PCBs in the soil amendment are being absorbed by or released from the plants. The Indian Lake Watershed Program has also applied for another 319 EPA Grant in which there will be funds allocated for this project to aid in the transport, mixing, and testing. Partnering is the only way to go for the future. As already known, the more residuals that get into the recycling stream, the more cost effective the whole project is. Also, bringing these residuals into the marketplace requires research, education, and incentives for new technology. Partnering can provide a multitude of skills needed to get a project up, running, and accomplished, such as; getting the players together, data collection, information processing, the distribution of and the education on the data results, getting funding initiatives, and gaining public acceptance.

There will be continuous evaluation of and education on the project. The Internet, news articles, and newsletters will be the primary mode of transfusion of information. The information will be used to present and share knowledge gained to civic and professional groups such as: Ohio Livestock Manure Ambassador Program, Young Farmers Groups, Ohio and National Pork Producers, and Conferences. It is anticipated this information will greatly increase public awareness regarding the importance of controlling Nonpoint source pollution and related watershed management concepts.

The commingling project is projected to basically have a three year period to get it off the ground and running. Once this is accomplished, the project will be placed in the hands of the swine producer, contractor, and State Parks. We as SWCD people are acting as the "catalyst", ie; get the resources together, then let the three main players handle the business, make money, and best of all, REDUCE, REUSE, RECYCLE. The thought for the future that starts now.

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