Pharmaceuticals in On‐Site Sewage Effluent and Ground Water, Western Montana

Abstract

Human use of pharmaceuticals results in the excretion and disposal of compounds that become part of municipal and domestic waste streams. On-site waste water disposal and leaking city sewer systems can provide avenues for the migration of effluent to the underlying aquifers. This research assessed the occurrence and persistence of 22 target pharmaceuticals in septic tank effluent and two shallow, coarse-grained aquifers in western Montana. Twelve compounds (acetaminophen, caffeine, codeine, carbamazepine, cotinine, erythromycin-18, nicotine, paraxanthine, ranitidine, sulfamethoxazole, trimethoprim, and warfarin) were detected in a high school septic tank effluent. Three of the 12 compounds, carbamazepine, sulfamethoxazole, and nicotine, were detected in the underlying sand and gravel aquifer after effluent percolation through a 2.0-m thick sand vadose zone. Sampling of a second sand, gravel, and cobble dominated unconfined aquifer, partially overlain by septic systems and a city sewer system, revealed the presence of caffeine, carbamazepine, cotinine, nicotine, and trimethoprim. The presence of carbamazepine and sulfamethoxazole in these aquifers appears to correlate with local usage based on a reported monthly prescription volume. This work highlights the need for expanding geochemical investigations of sewage waste impacted ground water systems to include sampling for selected pharmaceuticals.

Emerging organic contaminants in groundwater: A review of sources, fate and occurrence

“…Several case studies in the USA have reported a range of EOCs in groundwater impacted by septic tanks (e.g. Verstraeten et al, 2005;Swartz et al, 2006;Godfrey et al, 2007). Common PPCPs reported include ibuprofen, paracetamol, salicylic acid, and triclosan.…”

“…in the unsaturated and saturated zone, microorganisms are less numerous and probably less diverse and there are also variable redox conditions which may limit biological activity (Johnson et al, 1998). The degradation pathways of EOC are often significantly faster under aerobic conditions compared to anaerobic conditions Godfrey et al, 2007;Barnes et al, 2004). As such, redox controls are a common theme in EOC persistence in groundwater from a range of sources including landfills, septic tanks and CAFO lagoons.…”

“…Common sources of caffeine include septic tanks as well as waste water treatment discharge to surface water and groundwater-surface water exchange in alluvial groundwater systems (e.g. Swartz et al, 2006;Godfrey et al, 2007;Rabiet et al, 2006). Nicotine was only reported in two case studies (Stuart et al, 2011;Godfrey et al, 2007).…”

Transformation Products of Emerging Organic Compounds as Future Groundwater and Drinking Water Contaminants

“…Caffeine, nicotine and the nicotine metabolite cotinine are widely detected in groundwater impacted by sewage effluent (Godfrey et al, 2007;Seiler et al, 1999). Swartz et al (2006) showed caffeine and its paraxanthine metabolite were substantially attenuated during recharge of septic tank effluent.…”

Emerging Organic Contaminants in Groundwater

“…Caffeine, nicotine and the nicotine metabolite cotinine have been widely detected in groundwater impacted by sewage effluent [55][56][57]. The artificial sweeteners acesulfame, saccharine, cyclamate and sucralose have been found at high concentrations in groundwater impacted by sewage infiltration ponds [58].…”