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Redmond Tallow Drinking Water Wells and Surrounding Water Wells



On February 14, 2002, the Oregon Department of Human Services (ODHS) was advised by Deschutes County Environmental Health Department (DCEHD) of groundwater contamination related to historical and current rendering plant activities at Redmond Tallow, a privately owned and operated business in Central Oregon. In cooperation with county health personnel, ODHS evaluated the water testing data, recommended additional testing, and assessed the potential for human exposure to contaminated water on the site and in nearby private wells. The principalle contaminant of concern is nitrate ion, released into surface soil on the site. On the basis of the sampling data and known health effects of nitrates, ODHS considers this site to be a public health hazard.

As further investigation into the causes and the extent of the contamination are ongoing, ODHS has made interim recommendations to personnel on the site to avoid using the drinking water system unless and until the source of nitrate has been found and eliminated, and the groundwater nitrate levels have returned to background levels.


Redmond Tallow is a family owned and operated animal carcass rendering plant located on rural land in Central Oregon approximately three miles northeast of the city of Redmond, in Deschutes County. The rendering plant, is located on a 40-acre site, and consists of buildings which house the rendering plant facilities and of two unlined waste holding ponds. The residence of the owner/operator is also on the property, as are the homes of six to eight mobile homes that house employees of the rendering plant (Roger Everett, RS, Environmental Health Supervisor, Deschutes County Health Department, Bend, Oregon, personal communication, Feb. 14, 2002 and Mar. 18, 2002). All on-site facilities are provided water by a single water system consisting of two wells, pumps, and piping for distribution of the water. No disinfection or other treatment of the drinking water is provided.

The plant has operated continuously at the site since the early 1920s, disposing of large animal carcasses from the immediate vicinity; in recent years, the plant has been receiving and processing carcasses from all over the state, as the number of rendering plants has decreased statewide [12]. Carcasses from as far away as Tillamook, on the Oregon Coast, are now received and processed at Redmond Tallow.

The historical waste management practices are obscure, and it is reported that liquid and semi-liquid waste has been deposited in five on-site drill-holes that connect to lava tubes on the property (Roger Everett, personal communication, Mar. 18, 2002). There is also an unconfirmed report that waste has been injected by steam pressure into the ground via these drill-holes. Lava tubes are common in Central Oregon, having been formed by flowing volcanic magma [2]. As the lava cooled and solidified around the circumference of the flows, it left an open network of tubes through the ash, pumice, and soils of the Central Oregon region. Many of these deeper tubes, extending from deep in the earth to the surface of the ground, contain groundwater and are in communication with groundwater aquifers throughout the region.

The unlined waste lagoons and incidental spilling, dumping, and burying of organic animal waste on the property are also potential sources of groundwater contamination (Roger Everett, personal communication, March 18, 2002).


History of Concern About Nitrate in Groundwater:

In 2001, Deschutes County Environmental Health Department tested drinking water samples from the water system serving the rendering plant. Samples from the two source wells contained 24 parts per million (ppm) and 16 ppm nitrate-nitrogen (Roger Everett, personal communication, March 18, 2002). The well having 24 ppm provides domestic water to the households on the property. Also, adjacent property owners reported to the county environmental health office that they had found elevated levels of nitrate thought to be attributable to the rendering plant.

In March 2002, DCEHD and Oregon Department of Environmental Quality designed a well sampling study to evaluate all domestic wells located within a quarter mile of the rendering plant property [3]. They collected and tested water from 22 private wells on surrounding properties, and they retested the two onsite wells. Results are shown in Table 1. The on-site wells again showed nitrate-nitrogen levels of approximately 24 and 15 ppm. Tests of the 22 neighboring wells found 20 of them to have nitrate-nitrogen levels ranging from 0.5 to 1.8 ppm. Two of the 22 off-site wells were found to have 6.1 and 2.5 ppm nitrate-nitrogen. None of the off-site wells reached or exceeded the current EPA drinking water Maximum Contaminant Level (MCL) of 10 ppm nitrate-nitrogen [4].

Table 1. Nitrate-Nitrogen Results from Onsite and Neighboring Wells

Sample Number Nitrate-N Level (mg/L) Sample Number Nitrate-N Level (mg/L) Sample Number Nitrate-N Level (mg/L)
0021 24.3 009 1.49 018 1.53
0031 16 010 1.22 019 1.79
004 1.1 011 1.22 020 0.79
005 1.23 012 1.42 021 0.74
006 1.4 013 6.05 022 0.53
007 1.34 014 2.51 023/0272 0.52
008 1.34 015 1.58 024/0252 1.46
1 Samples 002 and 003 are from two on-site wells (all other samples are from neighboring wells)
2 Nitrate Level shown is the mean of two duplicate samples from the same well.

Oregon Department of Environmental Quality has ordered the owner/operator of Redmond Tallow to retain a private consulting firm to further evaluate and determine the extent of groundwater contamination at the site, and to propose remediation for any conditions found to be hazardous or unlawful [35].

Potential Health Concerns:

Nitrate-nitrogen in drinking water at levels above 10 ppm is potentially harmful to humans and animals that consume large quantities of water [5]. Nitrate-nitrogen causes methemaglobinemia in infants and in others who are susceptible to the disorder. Adult susceptibility can be congenital or it can be induced by occupational exposure or by medicinal exposure to a variety of amine-containing chemical compounds. Nitrate-nitrogen above 10 ppm in drinking water is also thought to contribute to early miscarriage in susceptible women and to increase risk of cancer in persons regularly ingesting the water.

Although specific testing for additional contaminants has not been performed to date, there is potential for other contaminants of concern to also be present in the groundwater. Rendering wastes contain numerous organic components other than nitrates, and plant operations potentially introduce inorganic chemical contaminants through cleaning agents, disinfectants, pesticides, and other process additives. The wells on the site have not been tested for a wider suite of organic or inorganic contaminants.

Regulatory Concerns

Under Oregon law and administrative rules, any water system serving more than four individual connections is classed as a "public drinking water system" and is subject to testing, reporting, and public notification requirements [6]. This system has not been so identified in the past, and has therefore never complied with testing and reporting requirements. The OPHS-DHS Drinking Water Program, as a result of this consultation, is in the process of registering the system and bringing it into compliance with drinking water rules. DCEHD, with assistance of ODHS, developed the handout "Deschutes County Health Effects Information-Nitrates." They visited each household on the Redmond Tallow site property, advising each household of the nitrate hazard, providing a handout, and recommending that residents not use water from the on-site system until the water is brought into compliance with all drinking water criteria, including the MCL for nitrate-nitrogen (Jeff Freund, Deschutes County Community Development, personal communication, Jul. 2, 2002; and Rachel Wood, Deschutes County Health Department, personal communication, Jul. 1, 2002.


OPHS-DHS concludes that the nitrate in the wells around Redmond Tallow could result in adverse health effects, especially in young children. On the basis of this information, ODHS concludes that this site is a public health hazard. ODHS concludes that the households with nitrate levels above 10 ppm should be provided alternate water.


ODHS recommends the following:

  1. That water from the present on-site wells not be used for any ingestion purposes, either in the residences or in the rendering plant;

  2. That the wells be tested for the full suite of regulated drinking water contaminants to determine whether chemicals of concern other than nitrate-nitrogen are present in the water;

  3. That the on-site water system be officially registered as a "public drinking water system" and that regular testing and reporting of results be instituted;

  4. That DEQ continue the requirement for full evaluation of the contamination plume, both on- and off-site and require appropriate remedial actions on-site and off-site if impacts are demonstrated;

  5. That the owner/operator of the on-site water system be required either to install treatment sufficient to remove any contaminants found in the water, or to develop alternative water source(s) that conform to all requirements of the Oregon Drinking Water program and federal standards for public drinking water supplies.

  6. That employees and tenants relying on the on-site water supply be informed on a continuing basis of the unsuitability of the water for ingestion purposes, and that any new employees or tenants be informed fully of the uncertainty about chemical contaminants and the demonstrated hazard from nitrate-nitrogen.


Kenneth Kauffman
Public Health Toxicologist
Environmental Services and Consultation
Oregon Department of Human Services


  1. Disposal and Recovery of Animal Mortality and Byproducts in Oregon, Oregon Department of Environmental Quality, June 2001.

  2. Lunar Base Simulations in Lava Tubes of the Pacific Northwest, AAAS Pacific Regional Meeting, Corvallis, OR, June 19, 1988.

  3. Report from Jeff Freund, Deschutes County Community Development Department to Deschutes County Board of Commissioners, Apr. 12, 2002 (based on laboratory analyses by Oregon Department of Environmental Quality Laboratory, Apr. 1, 2002).

  4. USEPA corrections to Phase V Synthetic Organic Chemicals rule, July 1, 1994 and Oregon Administrative Rules 333-061-0030 (1), May 2, 2002.

  5. Nitrate, Technical Bulletin, Health Effects Information, Oregon Health Division, Environmental Toxicology Section, June 2001.

  6. Oregon Revised Statutes ORS 448.115 (13), Oregon Administrative Rules OAR 333- 061-0020 (112), May 2, 2002.


The Redmond Tallow Public Health Consultation was prepared by the Oregon Department of Human Services under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the public health consultation was begun.

John R. Crellin
Technical Project Officer, SSAB, DHAC

The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health consultation and concurs with the findings.

Lisa C. Hayes
for Chief, State Program Section, DHAC, ATSDR

Table of Contents The U.S. Government's Official Web PortalDepartment of Health and Human Services
Agency for Toxic Substances and Disease Registry, 4770 Buford Hwy NE, Atlanta, GA 30341
Contact CDC: 800-232-4636 / TTY: 888-232-6348

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