Agricultural Pollution – Dairies

cow1.pngKnown internationally for our fine cheeses and yogurts, California’s dairy industry is the nation’s largest and is the single largest agricultural industry in the state.  In fact, one out of every five gallons of milk consumed in the United States is produced in California.  As farmers have become more efficient at producing milk products, the concentration of cows per acre has increased.  For a period in the late 1990′s, the area around Chino was home to the highest concentration of dairy cows in the nation.  With a mature dairy cow producing as much waste as 34 people –114 pounds of manure per day or 22.5 tons of manure per cow per year – water quality issues are a serious concern. (Image Courtesy: U.S. Department of Agriculture)

That is why Waterkeeper is committed to following the practices of the dairy industry in Orange, Riverside and San Bernardino Counties, to ensure their compliance with environmental regulations intended to protect our drinking and recreational water from harmful pollutants such as bacteria laden manure runoff.

How are Dairies Regulated in Southern California?

cows2.pngSouthern California is home to thousands of dairies, which are governed under a series of regulations depending on the number of dairy cows, their living conditions, and the susceptibility of contaminating nearby water bodies.  National Pollutant Discharge Elimination System (NPDES) permits are used nationally under the Clean Water Act to regulate pollution and are issued from the Environmental Protection Agency (EPA) or a state authority, which in California is the Santa Ana Regional Water Quality Control Board (Regional Board).  NPDES permits are generally not required for grazing-based farming operations, so only farmers who operate Animal Feeding Operations (AFOs) or Concentrated Animal Feeding Operations (CAFOs) need to receive NPDES permits.

San Jacinto Dairy Cows

AFOs: The Clean Water Act defines AFOs as operations where animals have, are, or will be stabled or confined and fed for a total of 45 days or more in any 12-month period, and where vegetation is not sustained in the confinement area.  (40 CFR 122.23)  AFOs concentrate animals, feed, manure, drinking water, wash water, and animal carcasses onto a relatively small area.  Whereas a family farm may have twenty dairy cows allowed to graze on pastures, fields or rangeland, AFOs keep cows in confined areas with a large number of other dairy cows where feed is brought to them.

CAFOs: An AFO is considered a CAFO based on either a facility’s animal population (700 + dairy cows), or whether the Regional Board determines that the facility is a significant contributor of pollutants to “Waters of the United States.”  Regional Board Order No. 99-11 determined all dairies under their jurisdiction (Orange, and parts of San Bernardino and Riverside Counties) shall be considered CAFOs due to their potential to contribute pollutants to the Santa Ana River and San Jacinto River.

What Kinds of Pollution do Local Dairies Produce?



Process wastewater: water used directly or indirectly in the operation of an AFO for any or all of the following:
  • Spillage or overflow from animal water systems;
  • Washing, cleaning, or flushing pens, barns, manure pits, or other facilities;
  • Direct contact swimming, washing, or spray cooling of animals; or
  • Dust control

The Santa Ana Region, which includes parts of Orange, Riverside, and San Bernardino Counties, is home to 168 dairy-related AFOs.  These AFOs include heifer ranches and calf nurseries, and contain about 251,000 animals: 113,000 lactating (milking) cows, 21,000 dry (pregnant) cows, 48,000 heifers (12-18 month old cows), and 69,000 calves (less than 12 month old cows).  One hundred and thirty seven of these facilities (with 185,000) are located in the Santa Ana River Basin, the remainder (with 65,000 animals) are located in the San Jacinto River Basin.

CAFOs generate manure, litter, process wastewater, and stormwater runoff from manure areas, which can contain high levels of pollutants.  Improper maintenance by CAFO operators may result in the release of these pollutants through spills, overflows, or runoff into local streams, rivers, and lakes.  About 10% of the milking cow manure is excreted in the milk barn, and about 90% is deposited in the corrals.  In 2006, approximately 940,000 tons of manure was removed from the corrals in the area.  The Regional Board estimates 7.9 million gallons of wash water, which contains approximately 10% of the manure generated by milking cows, is discharged to the ground each day.  CAFO waste contains high levels of ammonia, bacteria, biochemical oxygen demand, nitrate, phosphorus and other salt compounds.

sceniccafo.pngRunoff from the Chino Basin dairies drains to Chino Creek, Mill Creek and Reach 3 of the Santa Ana River, each of which are 303(d) listed impaired water bodies according to the State of California.  These water bodies are impaired due in part to CAFOs contributing nutrients, pathogens, salinity/Total Dissolved Solids (TDS)/chlorides, and suspended solids. Improper CAFO location, poor maintenance, and heavy rain events can cause wastewater lagoons (a dedicated pond holding dairy cow waste) to overflow into nearby water bodies.  Discharged water from the CAFOs affects the quality of groundwater in Orange County, because water from the Santa Ana River is captured by the Orange County Water District and percolated to recharge the Santa Ana Forebay Groundwater Subbasin.

Dairy runoff in the San Jacinto Basin affects the San Jacinto River, Lake Elsinore and Canyon Lake.  High phosphorus levels from local CAFO discharges are considered a major source of frequent algal blooms in Lake Elsinore.  The blooms cause a reduction in the lake’s oxygen levels, resulting in fish kills and prevent stable economic development.  In sum, when dairies significantly contribute to poor water quality, the local community bears the brunt of related costs, including: 1) direct costs such as treatment systems to mitigate water pollution, 2) indirect costs through shortened life cycles for water heaters, pipes, and other water related systems and appliances, and 3) recreational costs associated with damage to freshwater habitat.

How Large of a Problem is Agricultural Pollution from Dairies? 

conveyance.pngIn 2000, the National Water Quality Inventory reported agricultural pollution to be the leading source of water quality impacts on surveyed rivers and lakes, the second largest source of impairments to wetlands, and a major contributor to contamination of surveyed estuaries and ground water.  Two significant sources of agricultural pollution are 1) poorly managed and improperly placed AFOs, and 2) excessive or poorly timed manure or water application.

In a 1990 Dairy Report specific to Chino dairies, the Regional Board found the use of dairy manure as a fertilizer results in two to four times more salt reaching groundwater than the use of non-manure commercial fertilizers.  This fact is particularly troubling for the Chino Basin, which houses the vast majority of the region’s dairies and has severe TDS and nitrate groundwater quality problems.  When manure is used as fertilizer on crops in an amount greater than needed, excess salts that are not utilized by plants migrate to the groundwater basin.  In recognition of this finding, and chronic groundwater problems, the Regional Board limited the amount of manure that could be used in the Chino Basin.

The Regional Board has identified existing and potential beneficial uses of surface waters that could be impacted by the discharge of dairy waste in the Santa Ana Region to include: Municipal and Domestic Supply, Agricultural Supply, Industrial Service and Process Supply, to Wildlife Habitat, Marine Habitat, Shellfish Harvesting and Water Contact Recreation.  The Regional Board has also identified existing and potential beneficial uses of groundwater that could be impacted by dairy waste discharge to the Santa Ana Region include one or more of Municipal and Domestic Supply, Agricultural Supply, and Industrial Service and Process Supply.

The most common type of agricultural pollution is sedimentation, caused by soil that washes off fields.  When rainwater falls on crops covered with manure, the water carries soil particles to nearby streams and lakes.  Sediment can cloud water, reducing the amount of sunlight that reaches aquatic plants. In addition to reduced clarity, water carrying soil can cover fish eggs and prevent hatching as well as cause algal blooms and depleted oxygen levels, which contribute to fish kills.

Both Canyon Lake and Lake Elsinore, Southern California’s largest natural freshwater lake, are impaired due to phosphorus and nitrogen.  The Lake Elsinore/Canyon Lake nutrient Total Maximum Daily Load (TMDL) establishes load allocations for sources that contribute excessive nutrient loads to the lakes.  In order to decrease the amounts of phosphorus and nitrogen reaching the lakes, reductions must come from the San Jacinto CAFOs.  The Regional Board and CAFO operators are working to reduce nutrient loads from reaching these lakes.

The primary sources of organic nitrates include human sewage and livestock manure, especially from feedlots. As nitrates are highly soluble and do not bind to soils, they have a high potential to migrate to groundwater. High concentrations of nitrates in drinking water are an indicator of poor water quality and have been linked to miscarriages and “blue-baby” syndrome.  Blue-baby syndrome (methemoglobinemia) is a potentially fatal blood disorder in infants under six months of age where red blood cells cannot carry sufficient oxygen in the blood and the baby develops a slate-gray or bluish color.

What Sort of BMPs does Waterkeeper Support?

Before and After VSEP Treatment Vibratory Shear Enhanced Processing

dirty-water.pngWaterkeeper is interested in further research into the Vibratory Shear Enhanced Processing (“VSEP®”) system, developed by New Logic Research, Inc., of Emeryville, California.  VSEP is an experimental process that uses reverse osmosis (RO) membranes to separate and concentrate suspended solids and dissolved solids (primarily salts and nitrates) from dairy manure and wastewater (Stowell and Carter 2008). Pathogens, viruses, and bacteria are also removed and stay with the solids. The primary goal of the VSEP system is to concentrate solids, dissolved salts, and nutrients to facilitate improved dairy waste management, while recovering clean water for reuse on the facility including livestock drinking water.  (Source: San Jacinto Watershed Integrated Regional Dairy Management Plan, December 2009)

Conservation Buffers:

Conservation Buffers are strips of property between water bodies and farmland maintained in permanent vegetation.  Buffers include: riparian buffers, filter strips, grassed waterways, shelterbelts, windbreaks, living snow fences, contour grass strips, cross-wind trap strips, shallow water areas for wildlife, field borders, alley cropping, herbaceous wind barriers, and vegetative barriers.  These natural systems slow water runoff from agricultural activities, trapping nutrients, water, pesticides, and sediment within the buffer and can prevent these potential pollutants from reaching waterways.  Apart from reducing pollutant carrying runoff, conservation buffers provide wildlife habitat improvements, stream bank protection, and farm safety while improving the appearance of the farm.  Local, state, and federal agencies provide grant assistance and incentives to small farmers interested in incorporating conservation buffers through the Conservation Reserve Program, the Environmental Quality Incentives Program, the Wildlife Habitat Enhancement Program, the Wetlands Reserve Program, and the Stewardship Incentives Program. (Source: Department of Agriculture, Natural Resources Conservation Service)

Manure Disposal Policies:

The Regional Board has properly prohibited the disposal of manure to land in their jurisdictional area as well as prohibiting the application of manure from outside the area.  The Regional Board has also prohibited the application of manure, process wastewater, and/or storm water runoff from manure areas, or cropland outside of the Chino Basin (where most of the area’s dairies are located) that overlie groundwater management zones lacking assimilative capacity for Total Dissolved Solids and/or nitrate nitrogen unless a plan, authorized by the Executive Officer of the Regional Board, is implemented that offsets their effects on the groundwater.  Similarly, manure applied to non-CAFO related croplands that may affect groundwater with TDS or nitrate nitrogen problems can only be applied in the amount necessary for the crop (agronomic rate) and immediately incorporated into the existing soil unless appropriate controls have been taken.  The Regional Board’s 2009 San Jacinto Watershed Integrated Regional Dairy Management Plan found dairy manure to represent “by far the dominant source of salt and nutrient loads” in the San Jacinto watershed and that “80 percent of the dairies’ salt load could be eliminated by exporting all solid manure from the watershed.”  As such, proper manure disposal policies and effective enforcement are critical for water quality security in the San Jacinto watershed and beyond.

Structural Practices:

Waterkeeper encourages the adoption and implementation of structural best management practices (BMPs) designed to reduce the salt and nutrient loads delivered to surface water and groundwater resources, including: pond lining, multi-pond treatments, constructed wetlands, composting, and cooperative/regional digesters.  Where appropriate, Waterkeeper prefers constructed wetlands as a solution for reducing loads due to the diversity of beneficial side effects wetlands have on the environment, including habitat and breading areas.

In sum, dairy pollution in the Santa Ana River watershed is an important contributor to impaired water quality and Waterkeeper is dedicated towards ensuring the dairy industry and state agencies comply with the applicable regulations and take action when individual dairies fail to meet their environmental and regulatory obligations.   The task to comply with environmental regulations and remain in business is difficult for many dairymen, but the levels of pollution are simply too great in the Santa Ana River watershed and the impact of decades worth of industrial farming are being felt region-wide at great financial, health, and environmental expense.  Cooperation between all actors will be necessary if this type of water pollution will be resolved in the coming decades and Waterkeeper is committed to working with state regulators, dairy operators, local governments, and concerned citizens towards reaching quantifiable water quality improvements in our region.

Additional Information