Jb. Farrell et al., DEVELOPMENT OF EPAS NEW METHODS TO QUANTIFY VECTOR ATTRACTION OF WASTE-WATER SLUDGES, Water environment research, 68(3), 1996, pp. 286-294
EPA's 1979 and 1993 sludge regulations require that sewage sludge be r
educed in vector attraction before it can be applied to the land. In t
he 1979 regulation, satisfactory vector attraction reduction (VAR) cou
ld be demonstrated if treatment processes reduced the volatile solids
content of sludge by 38%. The 1993 regulation adds two alternative tes
t methods for aerobic sludges for determining whether VAR has been ade
quate. In the first method, specific oxygen uptake rate (SOUR) of the
sludge must be < 1.5 mg O-2/hr/g total solids, and in the second metho
d, the additional volatile solids reduction (AVSR) that occurs when th
e sludge is further digested for 30 days must be < 15%. Experimentatio
n with the new tests is described. Comparisons among the three methods
showed that the 38% VSR requirement and the SOUR test were equivalent
only near 20 degrees C. The AVSR test was more conservative than eith
er of the other tests.