U.S. Fish & Wildlife Service Migratory Bird Mortality in Oilfield Wastewater Disposal Facilities Wyoming Ecological Services Field Office - Environmental Contaminants Program

Commercial and centralized oil deadly to birds that come into contact ponds. The sodium crystals destroy field wastewater disposal facilities with them. A light sheen will coat the the feathers’ thermoregulatory and (COWDFs), pose a significant risk to bird’s feathers with a thin film of oil. buoyancy functions causing the bird to migratory birds and other wildlife Although a sheen of oil on the bird may die of hypothermia or from drowning. because they use large evaporation not immediately immobilize the bird, it Sodium intoxication can cause ponds (either passive or with aeration) will compromise the feathers’ ability to neurological impairment resulting to dispose of and treat oil and gas insulate the bird. The affected bird will in the bird’s inability to hold its head exploration and production wastes. ingest the oil when it preens its feathers upright. The bird’s head will droop into An estimated 500,000 to 1 million and suffer chronic effects. The bird the water and cause it to drown. birds are lost annually throughout the could suffer mortality depending on United States in oil field production the severity of the chronic effects and Surfactants and other chemicals skim pits and COWDFs. the amount of oil ingested. Mortality If the evaporation pond is receiving or morbidity may result depending on produced water from oil or natural the amount of oil coating the animal, gas wells, oil and gas production the species, prior condition of the chemicals, such as corrosion inhibitors animal, the amount of stress incurred and surfactants, could be present in by the animal after oiling, and weather the wastewater and could pose a risk conditions. to migratory birds. Extreme pH in the wastewater can also adversely affect Oily sludges soaked into the dike birds landing on the evaporation ponds. can seep back onto the pond surface, Surfactants (i.e. soap) are used to especially during the summer when free oil or gas from the reservoir rock Oilfield wastewater disposal facility. warm temperatures can mobilize the formation. USFWS/Pedro Ramirez, Jr. oil. Rainfall events or snowmelt will Wastewater in COWDFs is initially wash oil from the dike back into the When a bird comes into contact with discharged into a receiving pit to pond. water containing surfactants, the separate the oil from the water. The surfactant will reduce the surface greatest amount of oil tends to float Salt Toxicity tension of the water; thus, allowing to the surface in the skim pit. Water Birds using COWDF ponds with water to penetrate through the feathers from receiving pits is often sent hypersaline water can ingest the brine and onto the skin. This compromises to another pit or series of pits for and die from sodium toxicity or can the insulation properties of the feathers evaporation or other management. suffer chronic effects especially if a and subjects the bird to hypothermia. COWDFs are typically regulated by source of freshwater is not available The loss of water repellency by the state agencies with oversight by the nearby. Birds preening the salt feathers due to reductions in surface U.S. Environmental Protection Agency crystals off their feathers can ingest tension will cause the bird to become primarily under the Oil Pollution Act the salt (as little as 4 grams of salt water logged and the loss of buoyancy and the Resource Conservation and can be lethal to birds). During cooler will cause the bird to drown. Recovery Act. Migratory birds are temperatures, sodium crystallizes on protected by the Migratory Bird Treaty the feathers of birds landing in these Act. Companies may be held liable should migratory bird mortalities occur in COWDFs or oil pits.

Oil, Sheens & Hydrocarbons Oil on the surface of evaporation ponds can entrap birds. Birds can also ingest toxic quantities of oil by preening their oil-covered feathers. Oil also damages the insulation provided by feathers. Visible sheens on ponds are just as Oil-covered blue-winged teal in COWDF evaporation pond. USFWS/Pedro Ramirez, Jr. Solving the Problem References Solutions to migratory bird mortality at Esmoil, B. and S. Anderson. 1995. COWDFs are fairly simple and straight Wildlife mortality associated with oil forward. pits in Wyoming. Prairie Naturalist 27(2):81-88 • Use Closed Containment Systems - Closed containment systems should Gordus, A.G.; H.L. Shivaprasad; and be used to store oil at COWDFs. P.K. Swift. 2002. Salt toxicosis in ruddy Closed containment systems ducks that winter on an agricultural eliminate soil contamination and evaporation basin in California. Journal remediation expense. of Wildlife Diseases 38(1):124-131 Surfactants in evaporation ponds can cause bird mortality. USFWS/ • Keep Oil Off Open Ponds – Meteyer, C.U.; R.R. Dubielzig; F.J. Pedro Ramirez, Jr. COWDFs should be designed Dein; L.A. Baeten; M.K. Moore; to prevent oil from entering J.R. Jehl, Jr.; and K. Wesenberg. evaporation ponds. A contingency 1997. Sodium toxicity and pathology plan should be developed for associated with exposure of waterfowl the facility to ensure immediate to hypersaline playa lakes of southeast clean up of oil discharged into New Mexico. Journal of Veterinary the evaporation pond to prevent Diagnostic. Investigation 9: 269-280 wildlife mortalities. Russel, W.C.; G.L. Choules; and D.A. • Use Effective & Proven Wildlife Gauthier. 1981. Detergents and Deterrents or Exclusionary waterfowl. Journal of Zoo Animal Devices – If open-topped tanks Medicine 12:10-13 or pits will be used to store oil at the facility, effective wildlife Stephenson, R. 1997. Effects of oil and Eared grebe with salt crystals on exclusionary devices should other surface-active organic pollutants feathers. Hypersaline evaporation be installed to prevent wildlife on aquatic birds. Environmental ponds can result in bird mortality mortality. Netting appears to Conservation 24(2):121-129 due to salt toxicity. USFWS/Pedro be the most effective method Ramirez, Jr. of keeping birds from entering Trail, P. 2006. Avian mortality at oil wastewater evaporation ponds pits in the United States: a review of and skim pits. Flagging is not an the problem and efforts for its solution. effective deterrent. Environmental Management. 38:532- 544 • Implement Engineering Controls to Prevent Oil Discharge to Windingstad, R.M.; F.X. Kartch; R.K. Evaporation Ponds –Engineering Stroud; and M.R. Smith. 1987. Salt controls should be designed and toxicosis in waterfowl in North Dakota. implemented to prevent the Journal of Wildlife Diseases 23(3):443- discharge of wastewater containing 446 oil and surfactants into the evaporation pond.

• Dispose of Oil Field Wastewater by Deep Well Injection – Deep well Oil-covered elk calf found at edge of injection of oil field wastewater COWDF evaporation pond. USFWS/ eliminates the need for evaporation Pedro Ramirez, Jr. ponds. For more information contact: U.S. Fish & Wildlife Service Wyoming Ecological Services Field Office 5353 Yellowstone Road—308 Cheyenne, WY 82009 (307) 772-2374 http://www.fws.gov/mountain-prairie/ contaminants/contaminants1b.html May 2009

Grebes and ducks recovered at COWDF Evaporation pond with oil on surface. evaporation pond. USFWS/Pedro USFWS/Pedro Ramirez, Jr. Ramirez, Jr.