Nonylphenols (NPs) have been reported to disrupt endocrine function and sex
ual development in aquatic organisms at low concentrations. Environmental N
P burdens are predominantly derived from degradation of nonylphenol polyeth
oxylate surfactants. We detected NPs in discharge-associated riverine sedim
ents adjacent to 11 of 20 active sewage treatment plants (STPs) at concentr
ations up to 12,400 mu g/kg. While most previous studies have focused on ST
Ps, nonylphenols were observed in association with a variety of outfall typ
es. The highest sediment burden, 14,100 mu g/kg, was detected near a federa
l facility's stormwater discharge. Of 75 sediments examined from 67 sites,
45% contained NP concentrations >5 mu g/kg; median concentration in these N
P-positive sediments was 369 mu g/kg. Other surfactant-derived alkylphenoli
c compounds, specifically 4-tert-octylphenol and 4-cumylphenol, were observ
ed in two sediments at 8,220 and 70,000 mu g/kg, respectively. The maximum
NP concentration detected in an effluent, 6,300 mu g/L, was from a shipyard
oil/water separator. Nonylphenols were detected (> 1.0 mu g/L) in 20% of t
he 59 effluents examined; 10% exceeded 10 mu g/L. Sediments sampled near a
STP that had ceased treatment operations 20 years prior contained 54,000 mu
g/kg, indicative of long-term NP residence. Results indicate that NPs may
be released from diverse sources, concentrate in associated sediments, and
persist therein for extended periods.