GOOD GOLLY MISS MOLY!

In 2002, JEA (a water, sewer, and electrical utility in Jacksonville, FL) commissioned a state of the art Biosolids Reuse Facility replacing a plant that incinerated sludge and disposed of the ashes at a landfill. Instead of treating the sewage sludge as a waste product, this material was now processed into pellets for beneficial reuse as biosolids. That changed in the summer of 2004. Starting in April 2004 the concentration of one pollutant, molybdenum (Moly), in the pellets began to increase dramatically. Eventually the Moly levels exceeded the Table 1 ceiling concentration limit established in the 40 CFR Part 503.13 regulations for land application.The beginning of these exceedances meant the end of marketing and land application for the residuals. The only recourse was to haul pellets to the landfill resulting in high transportation costs and tipping fees. Working with JEA Operations and Maintenance (O&M) and other groups, the JEA Industrial Pretreatment (IP) department promptly began a root cause analysis to determine the source of the Moly and methods to reduce the pollutant levels below the ceiling concentration limit.Once the Moly sources were identified, JEA IP worked collaboratively with key external stakeholders to bring Moly levels below the ceiling concentration limit by using pollution prevention methodologies that were cost neutral for commercial customers. This paper describes the root cause analysis, sources of Moly, and the collaborative pollution prevention efforts used to return the biosolids to a marketable product.