AWWA ACE61597

Current United States federal regulations mandate that community water systems notexceed contaminant levels of 5 pCi/L for combined radium and 30 µg/L for uranium. Alltreatment technologies to meet these standards generate residues with elevated radionuclidecontent. Water treatment residues may consist of either liquids or solids, depending on thetreatment technology used to remove the radium or uranium. All or part of these residues may bemanaged directly by the water provider, enter public waste streams through sewers, or be directly transported to land disposal sites including Municipal Solid Waste (MSW) landfills.Liquid residues may be discharged to the sanitary sewer system and then to a wastewatertreatment facility (WWTF). Radionuclides in the residual liquids may be retained andconcentrated in solids in the sewage system and sludges (inorganic and biosolids) (Ainsworth etal., 1994) generated in the treatment facility. The WWTF sludges may then be disposed inlandfills, land farmed, or placed in evaporation lagoons or dedicated landfills. This paperprovides estimates of the radium concentrations that could be present in radium-bearing sewagesludge and solid water treatment residues that might be disposed in landfills, and estimates of theatmospheric radon concentrations that could result from such disposal.Mass balance calculations indicated that if sewage sludge containing radium from watertreatment commingled with municipal solid waste in proportion to per capita water use and solidwaste generation, the radium isotope activities in the resulting refuse would be very small andradon emissions would be insignificant. On the other hand, if the sludge disposal wasconcentrated in limited portions of the MSW landfill, numerical simulations indicated that radonemissions could result in atmospheric concentrations exceeding background directly above anddownwind of the landfill by a factor of up to 8. The operation of a landfill gas collection systemcould significantly increase emissions and atmospheric concentrations of Rn-222 and Rn-220. Includes 8 references, figures.

Product Details

Edition:

Vol. - No.

Published:

06/17/2005

Number of Pages:

12

File Size:

1 file