Biosolids -- treated sewage sludges -- have been "beneficially used" as soil amendments and fertilizers for decades. In 1993, the US Environmental Protection Agency finalized national regulations for the use and disposal of sewage sludge, the so-called "Part 503" rules. In 2006, the North East Biosolids and Residuals Association (NEBRA) received a contract from the USEPA to conduct a national survey on biosolids regulation, quality, end use and disposal in the US. The 2006 national survey collected data from 2004. Estimates were generated for every state, giving the first-ever comprehensive picture for the nation as a whole. Of the 7,180,000 tons reported used or disposed, 3,507,000 (49%) were managed via beneficial use; 3,252,000 (45%) were disposed; and 421,000(6%) were stored, or their final use or disposal was not reported. For a large percentage of wastewater solids (2,903,000 tons or 43%), there is no data regarding whether or not it met Class A or Class B standards.