From the caffeine in a morning cup of coffee to the deet in the insect repellant, these are among the chemicals being detected in waterways. They include pharmaceuticals and pharmaceutical’s metabolites, some of which are still biologically active. In a United States Geological Survey (USGS) Reconnaissance study that appeared in the USGS Technical Open-File Report 02-94, it was found that 80 percent of 139 streams sampled contained pharmaceuticals.
These pharmaceuticals were previously thought to have been introduced into the surface water by industrial and agricultural practices. But according to the study's data, an increase in pharmaceutical levels in surface water showed up immediately downstream from wastewater treatment plants that service the general population’s wastewater.
How are Pharmaceuticals Introduced into Wastewater?
When people consume medications, some of the medications are broken down in the body into metabolites. These metabolites enter the surface and groundwater systems through the sewage and also through field runoff (when excreted by animals). The pharmaceuticals are also deposited directly into the sewage system when unused drugs are disposed of.
Some of the un-metabolized drugs commonly found in the wastewater include triclosan (an antimicrobial found in soaps), and sulfamethoxazole (an antibiotic). With the demand for water on the rise in arid regions, municipalities are forced to look for alternative water sources, like reclaiming wastewater.
These reclamation plants according to Stephen A Spano differ from regular wastewater treatment plants by the use of additional processes that are designed to reduce the pharmaceutical concentrations and not completely eliminate them. The reclamation plants provide water for agricultural purposes and water to recharge the groundwater. The reclaimed water ultimately ends up back in the drinking water supply.
Effects of Waste Pharmaceuticals on Human Health
The full extent of the effect of these compounds is still an unknown. The effect of the overexposure of microbes to the antibiotics in the wastewater has been considered as a possible negative effect. In this case the bacteria develop resistance to the antibiotics making the antibiotics ineffective in treating humans.
Another possible effect is the estrogenicity of these products. The estrogenicity of the wastewater has been shown in lab tests of wastewater treatment plants effluents on native fish samples (Environmental Toxicology). In human beings, this estrogenic effect caused by some of the waste products acting as hormone disruptors is suspect in causing problems in the development of the reproductive system.
Treating Wastewater for Pharmaceuticals
Many pharmaceuticals are considered toxic waste by the Environmental Protection Agency (EPA). To regulate a drug manufacturing plant’s wastewater they are given water quality standards before discharging drugs and other chemicals into their wastewater.
These standards are contained within their federal National Pollutant Discharge Elimination System (NPDES) permit. This monitoring system is designed to controls the amount pharmaceuticals discharged from drug manufacturing plants.
Unfortunately, it is impossible to regulate individual homes wastewater; people rely on the effectiveness of their municipality's wastewater treatment plants to remove the water drugs. These plants are unable to remove all the pharmaceutical compounds.
The drug manufacturing plants are also unable to consistently remove these chemicals from their wastewater and continue to add to the surface water’s pharmaceuticals load.
What Can be done to Help Minimize Pharmaceuticals In Wastewater?
To ensure the safety of drinking water, it is important to get involved in the policy-making process, encouraging policies that protect water quality. Learn how to dispose of unused medications, pesticides, and cleaning products properly.
Any concerns about drinking water should be directed to the local water utility.