Hazardous Waste Program
Tannery Sludge Environmental Investigation
Hexavalent chromium testing in northwest Missouri
The Missouri Department of Natural Resources and the U.S. Environmental Protection Agency, with assistance from the Missouri Department of Health and Senior Services and the Agency for Toxic Substances and Disease Registry opened a cooperative investigation into the tannery sludge issue in late April 2009. The government investigation was launched in response to public concerns about a St. Joseph leather tannery's distribution of waste sludge for use as agricultural fertilizer on northwest Missouri farms, and whether the sludge material contained hexavalent chromium that might pose health risks to the public.
A meeting to discuss the findings of the department's investigation was held Tuesday, Nov. 9, 2010 at the St. Joseph City Hall Council Chamber in St. Joseph.
The final report is posted under the Full Scale Investigation of Residential Yards and Agricultural Fields header below.
These links will direct you to specific information on the different parts of the environmental investigation.
On May 1, 2009, department and EPA staff collected a total of eight soil samples from three farms in Andrew, Buchanan and DeKalb counties where sludge from Prime Tanning is known to have been spread. Hexavalent chromium was detected in five of the eight samples at levels ranging from 20 to 49 parts per million, or ppm. The department has performed some water testing, including samples from one private well and two ponds on separate properties. Hexavalent chromium was not detected in any of these samples. Results from the initial round of testing are posted below.
- Sampling results from initial round of testing
EPA and the Missouri Department of Health and Senior Services calculated a screening level of 86 ppm for hexavalent chromium in agricultural field soils and a screening level of 2 ppm for hexavalent chromium in residential yards. Hexavalent chromium has been shown to cause some forms of cancer, including nose, sinus and lung cancers. EPA and Missouri Department of Health and Senior Services are not aware of any studies showing hexavalent chromium is associated with primary brain or central nervous system tumors. The Department of Health and Senior Services provided the department with a 0.3 parts per billion, or ppb, screening level for hexavalent chromium in drinking water.
Shortly after the May sampling event, the department assembled a technical sample-planning team to develop a sampling plan for assessing the potential risk posed by the sludge applications. The team includes staff from many state and federal agencies. The Missouri Department of Natural Resources is the lead agency for tannery sludge related soil and water testing in northwest Missouri. Besides collecting soil samples from farm fields in a four county area, the department will collect samples from residential yards located near the farm fields.
The future and past activities of this team are summarized below.
- Selection of a subset of agricultural fields for sampling
EPA staff selected a group of sludge-applied fields to be tested. This group includes 15 parcels (19 farm fields) that represent high, medium and low rates of sludge application, and were chosen to include fields in all four counties. Sampling results from these 19 fields will be used to assess risk and to determine whether sampling at additional fields is needed. Residential yards and wells adjacent to or nearby these 19 fields will also be sampled. Background soil sampling locations have also been selected in each of the four counties.
- Obtaining access for sampling
Department staff obtained permission from most property owners for sampling of the fields, residential yards and wells.
- Agricultural field pilot study
The sampling team designed and implemented a pilot study in August 2009. Department staff collected 30 surface soil samples from a single sludge-applied field to provide statistical data needed to design a sampling approach for the full scale sampling of farm fields.
- Residential yard pilot study
The sampling team designed and implemented a pilot study in October 2009. The department collected 10 surface soil samples from a single residential yard adjacent to sludge-applied fields to provide statistical data needed to design a sampling approach for assessing residential yards.
- Private Drinking Water Well Sampling
In December 2009, 12 private drinking water wells were sampled. Nine of the wells were near or adjacent to a farm field where sludge had been applied. Three of the wells sampled were not near or adjacent to farm fields where sludge was applied. These were collected to determine background levels of hexavalent chromium in groundwater in northwest Missouri.
- Full Scale Investigation of Residential Yards and Agricultural Fields
In January and April 2010, department staff conducted sampling at 10 residential yards and 19 agricultural farm fields, including background sampling locations. Samples were analyzed for hexavalent chromium and other parameters.
The sampling shows that past sludge applications have resulted in concentrations of chromium (including the hexavalent form) present in farm fields, yards and private wells. However, the hexavalent chromium concentrations do not exceed the health-based screening levels established for this site by the Environmental Protection Agency and the Missouri Department of Health and Senior Services. Based on the data collected, past land application of tannery wastewater treatment sludge does not appear to have resulted in a health threat to residents or farmers living and working in the sludge application areas. Therefore, no further investigation of the site is planned and no cleanup is needed.
- Farm Field and Residential Yard Sampling and Analysis Plan
- Farm Field and Residential Yard Sampling and Analysis Plan Addendum
- Site Investigation Findings Report
- April Site Investigation Findings Report
- Final Report on Tannery Sludge Farm Field Investigation (Posted Nov. 9, 2010)
- Public Meeting
The Department of Natural Resources conducted an inspection of the St. Joseph sanitary landfill on May 21, 2009, to ensure the landfill is properly handling and managing the waste coming from National Beef Leathers. Department staff conducted a physical inspection of the facility and a records review to determine compliance with applicable solid waste and water protection requirements. None of the results from the inspection or sampling gave the department cause for concern about impacts to public health.
In April-May 2009, the department and EPA conducted a multi-media inspection of the facilities of National Beef Leathers located in St. Joseph. The purpose was to determine compliance with air, water and waste regulations. Inspectors found no violations of air or water regulations, but they did document violations relating to the treatment, handling and storage of hazardous wastes. None of the alleged violations would appear to have any impact on the levels of hexavalent chromium in sludge generated by the company. National Beef Leathers has been officially notified of the violations. A determination of civil penalties against the company for those violations is currently pending.
EPA is the lead agency for the investigation into National Beef Leather's facility. For more information, visit EPA's National Beef Leathers Sludge Investigation Web page.
- Cameron Environmental Investigation
- Missouri Department of Health and Senior Services
- EPA's National Beef Leathers Sludge Investigation Web page.