Androstenedione, E1, and progesterone were detected in several higher density residential ponds in concentrations ranging from 1.4–3.3, 1.2–3.0, and 0.72–6.5 ng L1; E1 was detected in one of these ponds at a concentration of less than 2.0 ng L1 (Standley et al., 2008). Swartz et al. (2006) reported the presence of steroid hormones and other endocrine disrupting compounds in groundwater affected by a residential septic system. E1 and E2 concentrations in the contaminated ground water were found to range from 49–74 ng L1 to 16–19 ng L1, respectively.