Recently, new rules for acceptable concentrations of radium and other radionuclides in New Jersey soils have been adopted. In addition, the DEP continues to work with water purveyors on alternative solutions for drinking water supplies that fail to meet radium drinking water standards. The results of these efforts have demonstrated the need to focus increased attention to radionuclides in residuals. Therefore, the DEP also plans to work closely with biosolids and other residual generators to determine the impacts on residual quality from radium and other naturally occurring radionuclides.

Natural sources of radiation include geologic formations and soils that contain uranium, radium, radon, and other nuclides that are radioactive. There are certain geographical areas of New Jersey where relatively high radium concentrations occur in ground water and a number of public drinking water supplies depend upon ground water as their source of water. Some of these supplies have radium levels that exceed the drinking water standard for radioactive material. In treating the drinking water to remove the radium, a wastewater is created, which may contain much of the removed radium. When this wastewater is discharged to the sanitary sewer, the radium can be reconcentrated in sewage sludge produced by the treatment plant. Two other domestic sources of radioactive materials in sewage are food and medical procedures. Radioactive materials in food are digested and discharged to the POTW when excreted. Bananas and brazil nuts are examples of food containing radioactive materials. Similarly, radioactive materials used in the diagnosis and treatment of medical conditions are also discharged to the POTW when excreted.

The purpose of wastewater treatment facilities is to reduce or remove pollutants from the wastewater. Their role is to ensure adequate quality of water before it is reused or discharged. Of special concern in wastewater treatment facilities is the fact that radionuclides can become concentrated in the biosolids that result from the treatment processes. Radionuclides enter the biosolids as a result of various treatment processes and can become further concentrated as biosolids are dried or burned.

The DEP has collected some data, and through a grant from the USEPA, plans to collect additional data on naturally occurring radionuclides in residuals, especially biosolids to be land applied. In addition, the DEP is requesting any available data regarding radionuclides in sewage sludge, domestic septage, or incinerator ash that other entities may have to assist in this effort. After sufficient data has been obtained, the DEP will determine if there is a need to propose amendments to the Sludge Quality Assurance Regulations (N.J.A.C. 7:14C), and/or the New Jersey Pollutant Discharge Elimination System Regulations to incorporate monitoring requirements for radionuclides.