The success or failure of every dairy farm in Washington is directly dependent upon appropriate stewardship of the land on which it operates. This relationship of dependence is so axiomatic among dairy farmers that they like to describe themselves as “the first environmentalists.” As one Washington dairy farmer put it, “We live on this land. We breathe its air. We drink its water. We eat the food grown from its soil. Are we really going to abuse that which keeps us alive?”
Responsible environmental practice on Washington’s dairy farms can be described with reference to three key components:
- Manure Management Facilities
- Manure Handling
- Record Keeping and Documentation
Recycling is at the heart of dairy farming. Dairy cows are themselves one of nature’s great recyclers. They give us milk from the foods they eat — and those foods include things that might negatively impact the environment were it not for the cow’s ability to consume them (please see the Nutrition section under “It starts with great cow care”). Whey — the liquid left over from the cheese-making process — is now a valued ingredient that boosts the protein value of many manufactured foods. Eventually, even the cow herself is recycled — her meat into food, her hide into leather, her bones into meal, practically everything finding a use.
Cows also give us manure. Most people think of manure as a problem, but in fact it is a nutrient-rich resource which — when properly managed — gives us nutritious food and displaces reliance on chemical fertilization (a potentially serious environmental impact). Manure is applied to crop lands as a natural fertilizer, yielding more and better foodstuffs such as corn — which is then fed right back to dairy cows. Through the agency of the cow, dairy farms play a key role in recycling nutrients and sustaining Washington’s agricultural lands.
Clean water is essential for drinking, for aquatic animal habitat and for recreational and industrial use. Dairy farm families are no less dependent on this essential natural resource than any other Washingtonians. Water is used by dairies for animal watering and cleaning, waste management and plant sanitation. Because it can come into contact with manure, waste water must be handled as a potential pollutant.
The principal guidelines for manure and waste water management by dairy farms are outlined in the Dairy Nutrient Management Act (NMA) of 1998, enacted by the Washington state legislature with support from Washington’s dairy industry. Purpose-designed manure management facilities, responsible manure handling practicesand accurate record keeping and documentation are the key ingredients in protecting Washington’s surface and ground water from manure contamination.
Manure Management Facilities
The NMA completely prohibits any discharge of manure-contaminated water by a dairy farm. Buildings used to house dairy cattle must be constructed and managed so as to contain manure within those facilities.
Dairy cows are commonly housed in barns. Manure generated in the barn must not be discharged from the building, so openings and gutters are designed to exclude storm water. To promote animal health and well-being, housing facilities are cleaned of manure frequently, either by mechanical scraping or with wash water. These systems must be built so as to result in zero discharges of manure from the facility.
The manure is transferred to a purpose-built storage facility, usually a so-called “lagoon,” where it remains safe until it can be used as a nutrient source via application to crop lands or exportation off the site.Milking parlors are thoroughly cleaned after every milking, generating significant volumes of waste water which may contain manure. This waste is also stored in the farm’s lagoon.
The lagoon can safely store manure for months, so it must be properly designed and of sufficient size to contain the materials. Lagoons are constructed so as to prevent seepage of their contents into ground water. Discharges of manure or waste water into surface or ground water — whether intentional or accidental — result in fines imposed on the dairy farmer by the Washington State Department of Agriculture. Potentially, they can also lead to criminal and/or civil action against the farm.
Manure is a natural, organic fertilizer that provides nutrients and organic matter beneficial to soil health and crop productivity. Using it as a fertilizer reduces or eliminates the need for chemical fertilizers with their potential for environmental impacts. The keys to the responsible use of manure as a fertilizer are the application rate (amount),timing, and placement of the application. Dairy farmers must also understand the nutrient density of the material as well as projected crop utilization to ensure a safe application.
- Application rate (amount): Application of manure must be at agronomic rates — that is, it must match the plants’ ability to absorb and utilize the nutrients it contains. Excess nutrients due to over-application can result in the over-accumulation of nutrients in the soil (including nitrogen, phosphorus and salts), leaching of nutrients to ground water (i.e., nitrate) or run-off into surface waters. Because manure contains natural bacteria, run-off due to over-application can contaminate surface waters. Dairy farmers adjust application rates to account for crop type, stage of crop growth, soil type, weather and time of year.
- Timing: Dairy farmers apply manure when soils are dry enough to retain and hold the nutrients without large surface pooling or run-off. Manure is applied with calibrated equipment to ensure that the proper amount is delivered. The use of spray applicators is being increasingly replaced by injection equipment that precludes wind-borne drift of material.
- Placement: When crop fields border surface waters, dairy farmers take additional measures to safeguard the adjacent body of water. Buffers (also known as setbacks) are areas between crop fields and surface waters where manure is not applied. Buffers serve as a fail-safe barrier in the event that run-off starts to occur. They capture the run-off and prevent it from reaching the surface water. Inclination of the field, amount and type of vegetation in the buffer and the amount and type of manure applied all factor in determining the width of the buffer. Buffer widths will change depending on the wetness of the season in which applications are contemplated. Attempts by government to impose permanent, fixed buffer widths are generally counterproductive because they ignore these variable factors.
Record Keeping and Documentation
Accurate record–keeping is a prerequisite to effective environmental management on the farm. As required under the terms of the NMA, all Washington dairies must have a written Nutrient Management Plan (NMP) that has been reviewed and approved by the local water conservation district.
The NMP is a technical document detailing manure management activities on farm and serves three primary purposes:
- To prevent discharges of contaminated waste water into surface waters such as streams, ponds or ditches
- To prevent migration of contaminants to ground water
- To supply nutrients to crops at an agronomic rate
The requirements of the NMP are determined by responsible state agencies. They contain a summary of the operations underway at the farm (acres of land, number of animals, crops under cultivation, manure storage facilities on site, etc.); a nutrient application schedule; soil analyses; and other data relevant to the protection of nearby surface and ground waters.
Operating a dairy without a NMP results in fines and other actions against the farm owners. Under the NMP, all manure applications must be adequately documented. The number of animals retained on the farm must not exceed that specified in the NMP, to ensure that manure amounts generated on farm can be safely absorbed without run-off into nearby surface waters
Manure management on Washington’s dairy farms is not conducted on the honor system. In fact, every Washington dairy is inspected at least once every 22 months by the Washington State Department of Agriculture to ensure that its facilities and management practices conform to its NMP and applicable state laws and regulations. Failure to conform can result in fines and other actions against the farm. NMPs are updated to reflect changes in management, animal numbers, crops under cultivation, physical infrastructure and other activities on farm, then re-submitted for approval.
Washington’s dairy farmers welcomed the environmental protection safeguards incorporated in the Nutrient Management Act and worked with the state legislature and state regulators to see them enacted. And the results have been good for Washington! According to the Livestock Nutrient Management Program’s “Report of Program Activities” for 2008 (most recent report available), state inspectors found that 96% of dairies they visited were in compliance with their NMPs.
The environmental stewardship enhancements introduced with the NMA are cited by regulators and independent experts as contributing significantly to marked improvements in the water quality of sites ranging from the Granger Drain and Yakima River in Yakima County; the Nooksack River Basin in Whatcom County; and the Chehalis River in western Washington.