Dairy Waste Treatment CIRCULAR ANR-963

ALABAMA A&M AND AUBURN UNIVERSITIES

ALA 'BAMA ,...... >~ C OOJ>IlRATTVE Planning And Managing Lagoons For ExtenSIOn SYSTEM Dairy Waste Treatment CIRCULAR ANR-963

airy waste lagoons are sign and management the anaer flush system lagoons do not Dearthen structures designed obic lagoon can function for need to be located quite so close for biological treatment and years. Odor from a well-designed to the dairy waste source. long-term storage of dairy waste. and well-managed lagoon will be Good engineering practice, L'flgoons are specially construct only slightly musty; foul odor in as recommended in ASAE ed to prevent leakage of dairy dicates a malfunction requiring EP403.3, calls for lagoons to be waste to ground water. The la corrective action. no less than 300 feet from any goon system allows manure to Advantages of anaerobic la water supply used for human be handled with water-flushing goon systems are: consumption. Natural Resources systems, sewer lines, pumps, • Manure can be handled Conservation Service (NRCS) rec and irrigation equipment. The with water flushing systems, ommends 500 feet but will ac natural biological action on the sewer lines, pumps, and irriga cept 150 feet from an upslope waste results in less odor during tion equipment. well. Alabama Public Health De land application. Nitrogen con • The high degree of stabi partment, Division of Environ tent of the waste is reduced in lization reduces odors during mental Programs Management lagoons by as much as 80 per land application. (Milk Inspection), will not permit cent. This reduction minimizes lagoons to be closer than 100 • High nitrogen reduction land area needed for land appli feet from the water supply on a minimizes the land area required cation and enhances long-term grade A dairy. for liquid effluent disposal. storage. Location of lagoons with re • Long-term storage is pro spect to nonoperator-owned res vided at low cost. Anaerobic Lagoons idences is an important consider Disadvantages of anaerobic ation. ASAE recommends a Anaerobic lagoons look like lagoons include: farm ponds at first glance. They minimum distance of 900 feet • Public perception that a la are larger than manure storage downwind. In Alabama, howev goon is an open container of basins, which do not provide er, recommendations are that la manure. 1 significant biological treatment goons be (1) located at least /4 or long storage periods, but • Offensive odors if improp mile from property lines and smaller than aerobic lagoons. erly designed and maintained. nonoperator-owned residences Even though aerobic lagoons are • Limited nitrogen availability and (2) screened from view with designed to provide a higher de if manure is used as a fertilizer. a natural or constructed screen. gree of treatment with less odor, In some situations, especially in anaerobic lagoons decompose Location Requirements north Alabama, the location of a more organic matter per unit lagoon will be controlled by soil Ideally, lagoons should be volume. Because of their treat and geological considerations. located downslope from the ment and storage capabilities ARCHIVEdairy freestall barn and milking anaerobic lagoons are a good center so that waste can be Soils Investigation compromise between storage drained or flushed to the lagoon Although printed county soil basins and aerobic lagoons. by gravity. If scraping waste is survey maps give general guid Anaerobic treatment of waste practiced, the lagoon should be ance, the dairy operator plan occurs without free m ..rygen to relatively close to the freestall ning a treatment lagoon should liquify or degrade high BOD barn. With a lagoon system, have an on-site subsurface soils (biochemical oxygen demand) waste is usually flushed with re investigation made. Agencies organic waste. With proper de- cycled lagoon water; therefore, with expertise similar to the NRCS can conduct on-site soils per thousand cubic feet. Typical storm. In Alabama, typical annu investigations and make appro recommended anaerobic lagoon al rainfall is at least 12 inches priate recommendations. Soil loading rate for dairy waste la more than evaporates from a borings or backhoe excavations goons in Alabama ranges from 6 free water surface. Dirt lot and are standard procedures to iden to 6.5 pounds of volatile solids berm runoff can also amount to tify shallow soil over coarse sand per thousand cubic feet per day. as much as 4 feet per year. This and gravel, crevice, limestone, or This is 1.5 cubic feet of perma volume from rainfall less evapo permeable bedrock. If any of nent volume per pound of live ration is held in the second stage these conditions exist, proce dairy animal weight. This of a two-stage lagoon and re dures and materials, such as clay amount can be reduced 20 to 35 moved when the lagoon is liners, geotextile liners, or con percent for dairy lagoon installa pumped. crete, to prevent seepage to tions where solids separation fa Sludge volume results from ground water must be used in cilities, which are highly recom manure solids entering a dairy construction. mended, are in use. lagoon and a portion remaining NRCS currently offers this Manure wastewater vol as bottom sludge. Research indi on-site soils and geologic investi ume provides for wastewater cates that approximately 0.19 gation assistance for animal storage of the accumulated ma cubic feet of sludge accumulates waste management structures as nure volume over the designed per year per pound of total dairy part of the animal waste man treatment period. Pump-down cow liveweight adding manure agement technical assistance interval and manure treatment to the dairy lagoon. With solids program. They should be con period are the same and should separation, sludge accumulation tacted for assistance. This be 180 days in Alabama. Storage would be less. The sludge accu process will determine the soil volume per pound of live dairy mulation rate can be used to de suitability for and final location animal weight is 0.5 cubic feet termine volume necessary for of a dairy waste lagoon. for 6 months. Longer treatment sludge over any particular cho time offers greater flexibility in sen design time, most commonly Lagoon Design scheduling pumping operations. from 12 to 15 years. Recom Volume Surface runoff volume mended sludge volume is 0.5 provides storage for rainfall cubic foot per pound of average Proper design of an anaero runoff plus any wash water or dairy live weight bic lagoon requires the calcula other freshwater that may be Freeboard volume is the tion of volume that will be need used for cleaning buildings or lot minimum extra depth above ed to accommodate waste areas. This volume is removed total full pool level, usually 1 accumulation over the desired from the lagoon during pumping foot, after all other volume re treatment period. Total lagoon operations. In Alabama, runoff quirements are met. volume of either a one-stage or from open concrete areas can Figures 1 and 2 show a cross a two-stage system is composed amount to a depth of more than section of one- and two-stage la of several parts (see Figure 1): 4 feet per year over the entire goon designs, which may be • Treatment volume. surface. Reducing the area used throughout Alabama. Sur • Manure wastewater vol where runoff drains directly into face area will vary with depth. ume. the lagoon will prevent unneces ·• Surface runoff volume. sary pumping. Surface water, un less needed for filling or dilu Two-Stage Lagoons • Net rainfall (rainfall minus tion, should be diverted away Where space is available, a surface evaporation, including from the lagoon. Generally the two-stage lagoon should be con the 25-year-24-hour storm). amount of rainfall and runoff to structed to improve wastewater • Sludge volume. be collected and stored in the la treatment and management flexi • Freeboard volume.ARCHIVE goon is figured on the wettest 10 bility. For dairy operations that Treatment volume provides years for net rainfall less evapo recycle lagoon liquid for open enough dilution volume for the ration on lagoon surface plus gutter flushing where animals breakdown of volatile solids by berm runoff. have direct access to flush water, bacteria and is not removed Netra~all.Thelagoon a two-stage lagoon provides from the lagoon during pump must provide storage for the net some insurance against disease down operations. This volume is gain of rainfall minus surface organisms being returned from based on the volatile solids daily evaporation plus the berm area the first stage before a reason loading rate in pounds per day runoff plus the 25-year-24-hour able die-off period. In addition

2 manure wastewater volume stop pumping

Figure 1. Capacity of single-stage anaerobic lagoon.

manure sludge volume wastewater volume 2-ft. minimum volume for recycle

FIRST STAGE SECOND STAGE TreatmentARCHIVE Storage And Treatment Figure 2. Capacity of two-stage anaerobic lagoon.

3 to further treatment, the second slopes below the waterline are both proper volume and seal stage also stores treated waste 2:1 though this depends on soil construction. water for irrigation. This treated type and structure design. Lagoon embankments wastewater can be irrigated An emergency spillway should be constructed to allow through small diameter sprinkler should be provided to protect for usual settling of 5 percent. nozzles. the dam in case of extreme The embankment should be The second stage should flooding. The spillway should be planted with a cover grass to allow for a permanent volume placed a minimum of 1 foot prevent erosion and must be that cannot be pumped (2-foot below the top of the berm, and large enough to accommodate minimum), wastewater volume allowance for settling should be mowers. Suitable fill materials for the waste treatment period made. It should also be located should be free of sand, roots, (180 days minimum), lot runoff as close to natural ground level stones more than 6 inches in di volume for the desired treatment as possible and as far as possible ameter, and other objectionable period, net rainfall on both from a corner location. The spill material. The minimum moisture stages, and space for the 25-year- way is intended for use in flood content of the fill material and 24-hour storm for both stages conditions and is not to be used foundation should allow the for (see Figure 2). The first stage will as a drain instead of pumping mation of a ball that will not contain only treatment (perma down the lagoon. separate when squeezed by nent) volume and sludge storage. hand. Experience has shown Construction that with suitable soil material Lagoon Design (with enough clay content), Techniques three passes of a sheepsfoot Geometry Proper lagoon construction is roller per 6-inch fill lift. on the Dairy waste lagoons can be essential to ensure protection of embankment or bottom seal will designed in a variety of shapes. ground water resources as well provide adequate compaction However, circular or square la as to provide a system that will for sealing. goons allow easier mixing with operate effectively for many A cutoff trench may be re propeller or pump type agitators years. Most guidelines for ac quired to remove sand, gravel, and are usually less expensive to cepted lagoon construction tech or other water-conducting mate construct. When rectangular la niques include: rials to prevent leakage under goons are constructed, a 4:1 • Site preparation. the embankment. length to width ratio should not • Excavation. Sealing is required on the be exceeded to encourage even • Embankments. bottom and sides of the lagoon distribution of manure. • Cutoff trench. to protect ground water. Seal Typical lagoon depths range construction guidelines generally • Sealing. from 8 to 20 feet, with a mini call for overexcavation and then mum depth of 8 feet. The specif Site preparation requires backfilling and recompaction of ic footage depends on animal that all trees, grass, and organic seal materials in thicknesses not numbers, runoff area slope, and material be removed. Topsoil exceeding 6 inches compacted underground geology. Deeper should be stockpiled close to the depth (not more than 9 inches lagoons offer several advantages, construction site for later place deep for compaction). ment on the top and exposed including less land needed be The lower 6 inches of the sides to allow good establish cause of smaller surface area re bottom seal may be scarified and ment of grass. After stripping, quirement, more thorough mix compacted in place to eliminate the foundation area should be ing of lagoon contents by rising removal and replacement. In prepared to bond with the fill. gas bubbles, more efficient me general, a minimum of 1-foot Loose dry material should be re chanical aeration, and minimum thick clay seal must be provided moved, and the foundation area · odor. ARCHIVEon the bottom and sides of a la scarified, disked, adjusted for The dike for a lagoon must goon. The deeper the lagoon, moisture, and compacted as nec be a minimum of 8 feet wide. the thicker the required seal, up essary. Slopes on earthen dikes and to or beyond 4 feet for a water banks generally range between Excavation requires the re depth of 25 feet. moval of rocks, sand pockets, 2:1 and 3:1. For good grass Some soils require soil gravel, and other materials not cover establishment and safe amendments such as bentonite, suitable for sealing. The excava mowing, slopes of 3:1 or better soda ash, or artificial liners to tion should be deep enough for are recommended. Generally, obtain a proper seal. Most prop-

4 erly planned dairy waste lagoons goon renovation. This requires systems provide ideal loading receiving raw manure eventually continuous agitation with spe conditions for lagoons. seal, limiting soil permeability to cially designed propeller or If foul odors develop in an as little as 10-6 em/sec. Immedi chopper pump agitators during anaerobic lagoon, the pH level ately after construction, the la the pump-out procedure. For should be checked. A pH read goon seal should be covered further information see Exten ing can be made using soil test with water (at least 2 feet deep sion Circular ANR-953, "Using Ir ing equipment or litmus paper. above the highest bottom eleva rigation To Renovate Livestock The addition of hydrated lime tion) to prevent drying and Lagoons." will increase a pH that is too low cracking. (less than 6.5). A higher pH will Management increase the activity of methane Solids Exclusion And bacteria and decrease the acid Procedures concentration. If this treatment Agitation Proper management is essen does not greatly reduce and con Bedding, fibrous material, tial to ensure that a lagoon func trol foul odors, the lagoon is and some manure solids break tions effectively and efficiently probably overloaded. down very slowly or not at all in during its expected lifetime. Lagoons usually fill to design a lagoon. This nondegradable Good design and well-executed capacity within 2 to 3 years of material leads to excessive construction are worthless if the start-up with the accumulation of sludge buildup and to a crust lagoon is not properly managed. wastes and rainfall on the open forming on the lagoon. Both For a lagoon system to oper lagoon surface. To prevent la sludge buildup and crust forma ate successfully, start-up proce goon overflow, excess lagoon tion interfere with the pump-out dures must be followed careful liquid should be applied to procedure. As much of these ly. A new lagoon should be grassland, cropland, or wood solids as possible should be sep filled with water to 60 percent of land at rates within the soil infil arated out of the manure waste treatment volume before manure tration capacity and the fertilizer stream and kept from entering is introduced. This assures suffi requirement of the vegetation. the lagoon. If not, over time the cient dilution for the establish Lagoons should be pumped dur accumulated solids will reduce ment of bacterial activity and ing the growing season to allow waste treatment volume and will also minimize start-up enough storage space for waste cause "overloading" of the la odors. Starting a lagoon in late water accumulation through goon. This "overloading" causes spring or early summer will winter when crop growth and increased odor and reduced allow a good bacterial popula nutrient requirements are low. waste treatment function. tion to be established during the The lagoon liquid should be As accumulated solids build warm season. sampled and analyzed to deter up into the waste treatment vol After initial start-up, lagoons mine its nutrient content. Table 1 ume, they should be removed to perform best when they are gives information on average prevent overloading by a special loaded continuously. Flushing dairy lagoon liquid accumulation pump-out procedure called Ia-

Table 1. Fertilizer Nutrients In Dairy Lagoon Liquid. Total Lagoon Plant Available Nutrientsb Total Anaerobic Liquid To Be Total Lagoon Liquid Irrigateda/ Nutrients Capacity, Irrigated Soil Incorporated Cow/ Plant Ft3/Cow Year Nutrient Lbs./ Lbs./ One Two-Stage Acre- Lbs./ Lbs./ Lbs./ ARCHIVEGallons Cow/ Cow/ Stage 1st+ 2nd Inch Acre-Inch Acre-Inch Acre-Inch Year Year 4,200 2,100 + 9,308 0.34 N 137 69 24 96 33 2,100 PzOs 77 54 19 67 21 K 20 195 146 so 156 53

"Estimated total lagoon liquid includes total liquid manure plus average lagoon surface rainfall surplus; does not account for seepage. blrrigated: sprinkler irrigated liquid, uncovered for 1 month or longer. Soil incorporated: sprinkler irrigated liquid, plowed or disked into soil within 2 days.

5 Table 2. Land Application Rate For Irrigated Dairy Lagoon Liquid. a Rate- Cereal Tifton44 Bermuda Limiting Corn Fescueb Tifton44b Grain Bermudac Hay Nutrient Maximum Pounds Per Acre Per Year N 100 150 200 275 325 400 PzOs 50 60 75 75 85 100 K20 80 100 100 225 260 300 Inches Per Acre Per Year N 1.4 2.20 2.90 4.00 4.7 5.8 PzOs 0.9 1.20 1.40 1.40 1.6 7.4 K20 0.5 0.68 0.68 1.54 1.8 2.0 Minimum Acres Per Cow N 0.24 0.16 0.12 0.09 0.07 0.06 PzOs 0.38 0.32 0.25 0.25 0.22 0.19 K20 0.68 0.50 0.50 0.22 0.19 0.17 aN P 0 leaching and denitrification and 2 5 soil immobilization unaccounted for. bopen grazing. ccontrolled grazing.

rates and estimated available nu remain at safe levels. Electrical marked by a treated post on the trient contents. Table 2 estimates conductivity (EC) is a convenient inside slope of the last stage). application rates and minimum field measurement that indicates In a one-stage lagoon, per land areas needed for dairy la salt content. Before the salt con manent markers should be in goon liquid irrigation application tent reaches 2,000 to 3,000 mil stalled (1) at a mark 1 foot for different crops. ligrams per liter (electrical con below design water level to Wastewater irrigation using ductivity of 3 to 5 millimhos per show when to initiate pumping regular irrigation equipment is centimeter), the lagoon should the lagoon and (2) at the lagoon the easiest and most cost effec be pumped down and fresh treatment level to indicate when tive way to apply lagoon liquid water added. This will reduce to stop pumping (see Figure 1). to land. Irrigate lagoon liquid on the chance of bacterial inhibition In a two-stage lagoon, a perma days with low humidity and and the formation of magnesium nent marker is needed only in when winds are not blowing to ammonium phosphate or stru the second stage to indicate ward neighboring residences. Ir vite. This struvite may form on when to initiate pumping. rigating in the early morning and the inside of pipes and pump Pumping out too much effluent early in the week will reduce of impellers in the recycled flush is not a problem in the second fensive odors. system, eventually causing stage if the 2-foot minimum For more information on breakdown. For information on depth remains to allow recycle land applying dairy waste from addressing this situation see Ex pump operation (see Figure 2). lagoons refer to Extension Circu tension Circular ANR-860, "Con The first stage is pumped only to lar ANR-925, "Calibrating Travel trolling Salt Buildup In Waste remove accumulated solids ing Guns For Slurry Irrigation." water Recycling Systems." which reduce permanent treat Procedures described apply to Pumping operations should ment volume (lagoon renova wastewater irrigationARCHIVE from la be started before the lagoon is tion, once every 5 to 20 years, goons. full to assure space (safety vol depending on design). As lagoons age, salt concen ume) is always available to hold trations may increase to levels a 25-year-24-hour storm. Good that can inhibit bacterial activity. management guidelines call for Salt levels in lagoons should be pumping the lagoon when the monitored yearly to ensure they water level reaches 1 foot below the design water level (usually

6 Appearance And Safety References A dairy waste lagoon should Agricultural Waste Manage be as aesthetically pleasing as ment Field Handbook. 1992. Part possible. Berms and embank 651, National Engineering Hand ments should have good grass book. Soil Conservation Service. cover for appearance and ero ASAE Engineering Practice: sion control and be mowed and ASAE EP403.3. Design Of Anaer maintained on a regular basis. A obic Lagoons For Animal Waste well-maintained lagoon is less Management. ASAE Standards, likely to attract attention and 1996. St. Joseph, Missouri. cause controversy. A fence Barker, James C. 1995. La should be provided to prevent goon Design And Management access by children, trespassers, For Livestock Waste Treatment and livestock. Warning signs And Storage. Circular EBAE 103- (SEWAGE TREATMENT FACILI 83. North Carolina Cooperative TY-KEEP OUD should be Extension Service. NC State Uni posted and any access gate versity, Raleigh, North Carolina. locked. Sweeten, John M. 1983. Dairy Manure Handling Systems And Equipment. Circular B1446. Texas Agricultural Extension Ser vice. Texas A&M University Sys tem, College Station, Texas.