Pharmaceutical Contamination Impacting Our Groundwater

Water is neither created nor destroyed. All the water on earth is between 4-5 billion years old, dating from around the time when the Earth was formed. There is no mechanism on Earth for creating or destroying large quantities of water. What we've got is recycled through the water cycle over and over again. Mankind leaves contaminants in the wastewater we return to streams. For most of history this was not important because contaminants were natural and biological, populations were sparse and the water ultimately flowed to the sea and rainwater returning to our rivers was free of contamination. As populations increased we treated our wastewater to remove the biological contamination with increasing efficiency to reduce disease and environmental impact. Wastewater reuse has become an important and measurable portion of downstream water supply while becoming a complex mix of chemical and biological contamination characteristic of our modern society. This contamination is spreading to all of our water supply including groundwater.

Groundwater is the largest and most reliable source of freshwater on earth. In the United States 26% of public supplied water is from groundwater in addition, 15% of households in the United States with private wells pump directly from groundwater for their drinking water. Groundwater and surface water are connected in many ways, not all of them fully understood. When streamflow is low due to lack of precipitation (drought) or withdraws (pumping for irrigation or water supply), groundwater serves to help maintain the baseflow. When conditions are dry, rivers, streams and ponds can serve to recharge groundwater.

In addition wastewater from agricultural irrigation is used to recharge groundwater and effluent discharge from wastewater treatment plants is intentionally and accidently finding its way into groundwater. In Los Angeles waste water effluent is used to recharge the groundwater, septic systems return their effluent water to groundwater and several studies by the U.S. Geological Survey (USGS) scientists Paul M. Bradley and Larry B. Barber (and others) have shown that waste water contaminants including pharmaceuticals are carried not only downstream into drinking water intakes, but into the shallow groundwater at least 65 feet from the stream.

The most recent study by Bradley and Barber et. al. was carried out at Fourmile Creek, near Des Moines, Iowa in October and December 2012. Fourmile Creek has been extensively studied by these scientists because wastewater dominates the streamflow. (Wastewater also dominates the flow of the Occoquan River and many others in our area.) Due to a drought in the Des Moines area, the wastewater represented 99% of streamflow in October and 71% of streamflow in December. Scientists chose to track the movement of pharmaceuticals between the stream and shallow groundwater because pharmaceuticals are bioactive, can be highly mobile, are good indicators of domestic wastewater, and wastewater is the only source of pharmaceuticals in Fourmile Creek.

Both stream and shallow groundwater samples were analyzed for 110 pharmaceuticals. The scientists found that 43% and 55% of pharmaceuticals analyzed for were detected in the stream’s water in in October and December, respectively. Fewer pharmaceuticals were detected in shallow groundwater; however, 16% and 6% of the pharmaceuticals were detected at a distance of 65 feet from the stream bank during October and December, respectively. The pharmaceuticals detected included antivirals and antibiotics, muscle relaxants, and antidepressants and tranquilizers, as well as medications for treating cancer, diabetes, and hypertension; in concentrations as high as 87 nanogram per liter (ng/L).

Both carbamazepine and sulfamethoxazole (a common antibiotic) were found in shallow groundwater at detectable levels at 65 feet from the river bank. The levels of these pharmaceuticals were higher close to the riverbank during the drier period, and appeared to fluctuate in response to drought; the larger portions of the river flow were made up of wastewater the higher the concentrations of sulfamethoxazole and carbamazepine in the groundwater. However as distance increased, the concentrations dropped, but it appeared that the rate of biodegradation of wastewater contaminants in groundwater is slower than in surface water and trace contamination of the groundwater may become ubiquitous.

USGS scientists have previously documented adverse impact to trace levels of sulfamethoxazole far below levels used to treat diseases on native soil bacteria. Since many studies by the USGS have found sulfamethoxazole in surface waters, the scientists conducted a series of laboratory experiments to determine the effect of the antibiotic on native soil bacteria. They found that sulfamethoxazole concentrations commonly found in aquatic environments (approximately 1 microgram per liter [ug/L]) delayed the start of cell growth, limited denitrification (a critical component of global nitrogen cycles), and altered bacterial community composition. In short, our contamination of water supplies with traces of antibiotics may impact the ability of the earth to feed us.

Other impacts of water pollution have been to the aquatic ecology. For over 15 years the USGS has been studying fish kills. Work done by Vicki Blazer and others has documented endocrine disruption and immune-suppression in aquatic life as contributing to fish kills. The earliest work did not find a cause. Dr. Blazer and others believe that methodology used to detect these chemicals in past studies may not have been sensitive enough, and may indeed be above the concentration thought to impact these fish. Dr. Blazer and others believe based on research studies in more than 25 fish species, that 1 ng/L (parts per trillion) may be the “no effects level” for estrogen concentrations in stream water on fish. We eat the fish, we drink the water, and we intentionally recharge groundwater with our waste water and pass all manner of chemicals and pharmaceuticals through our septic systems. For many of us, the closest septic system to your well is our own septic system. Any drugs you take (or flush down the toilet), chemicals you spray in your yard, use or pour down the drain may reappear in trace levels in your well especially during dry months or drought.

Water is our most valuable resource and how we manage its use or allow its abuse may determine the fate of our country and mankind. Groundwater is an important natural resource, especially in those parts of the country that don't have ample surface-water sources, such as the arid West and in times of drought. Groundwater is a renewable resource, but not in the way that sun light is. Groundwater recharges at various rates from precipitation and surface water. Wastewater reuse is necessary to meet water supply needs, but we are contaminating our environment and our drinking water supplies with what we do not remove from our wastewater.

Wastewater has become a complex mixture of chemical and biological contamination. Pharmaceutical contamination in wastewater is a particular problem because the pharmaceuticals are highly soluble in water, highly mobile in the water compared to other wastewater contaminants, and pharmaceuticals are designed to be highly bioreactive with long shelf-lives. At the low levels found they can be toxic to stream ecology, cause endocrine disruption, immune-modulation and suppression and serve for antibiotic resistance selection. Water contamination will challenge mankind’s survival long before climate change.

Related blog posts and articles:

Endocrine Disruption and What’s in the Potomac River Watershed

Is Our Drinking Water Safe?  

Barber, L., Keefe, S., LeBlanc, D., Bradley, P., Chapelle, F., Meyer, M., Loftin, K., Kolpin, D., Rubio, F., 2009. Fate of sulfamethoxazole, 4-nonylphenol, and 17bestradiol in groundwater contaminated by wastewater treatment plant effluent. Environ. Sci. Technol. 43, 4843e4850.

Barber, L., Antweiler, R., Flynn, J., Keefe, S., Kolpin, D., Roth, D., Schnoebelen, D., Taylor, H., Verplanck, P., 2011a. Lagrangian mass-flow investigations of inorganic contaminants in wastewater-impacted streams. Environ. Sci. Technol. 45, 2575e2583.

Barber, L., Keefe, S., Brown, G., Furlong, E., Gray, J., Kolpin, D., Meyer, M., Sandstrom, M., Zaugg, S., 2013. Persistence and potential effects of complex organic contaminant mixtures in wastewater-impacted streams. Environ. Sci. Technol. 47, 2177e2188.

Bradley, P., Barber, L., Kolpin, D., McMahon, P., Chapelle, F., 2007. Biotransformation of caffeine, cotinine, and nicotine in stream sedimentseImplications for use as wastewater indicators. Environ. Toxicol. Chem. 26, 1116e1121.

Bradley, P., Barber, L., Kolpin, D., McMahon, P., Chapelle, F., 2008. Potential for 4-nnonylphenol biodegradation in stream sediments. Environ. Toxicol. Chem. 27, 260e265.

Bradley, P., Barber, L., Duris, J., Foreman, W., Furlong, E., Hubbard, L., Hutchinson, K., Keef, S., Kolpin, D., 2014. Riverbank filtration potential of pharmaceuticals in a wastewater-impacted stream. Environ.Poll. 193, 173-180.

Update on Endocrine Disruption in Water Supplies

From USGS paper cited below

Earlier this month Vicki Blazer of the U.S. Geological Survey published a new paper, “Indicators of Reproductive Edocrine Distruption in Fish in the Chesapeake Bay Watershed.” Dr. Vicki Blazer is a mairine biologist and researcher at the U.S. Geological Survey, USGS. Dr. Blazer received the American Fisheries Society 2010 Publications Award for her article investigating the mortality of fish in the Potomac River basin and is a fish biologist at the West Virginia Science Center studying the impact of contaminants of emerging concern in rivers and streams of the lifecycle and health of fish on the Chesapeake Bay and its tributaries. This paper is a summary of the most recent research (previously published) by the USGS and others on endocrine disruption in fish in the Chesapeake Bay watershed and the implications to our lives.

The Chesapeake Bay watershed feed the Chesapeake Bay, the largest and most productive estuary in the United States. It serves as a nursery ground for the fish and shellfish industry and protects the coast from storm surges and filters pollution. The estuary filters water that is carrying nutrients and contaminants from the surrounding watershed. The nutrients in proper balance bring fertility, but excess nutrient contamination to the Chesapeake Bay has caused degradation in the habitat and impact to fish and other animals. As a result, US EPA has taken control of the situation and has developed a new federally mandated TMDL (total maximum daily load) to try to restore the natural balance in the estuary by controlling nutrients in the local waters. The TMDL addresses pollution from phosphorus, nitrogen and sediment and allocates a pollution budget among the states which will decrease over time. However, according to Dr. Blazer, the fish (and other aquatic organisms) in the Chesapeake Bay watershed are being exposed to a complex mixture of chemicals that may have additive, synergistic or antagonistic effects.

In the Potomac River watershed, largemouth bass show signs of feminization (testicular oocytes and vitellogenin in males) but appear to be less sensitive than smallmouth bass to the effects of estrogenic compounds. The scientists discovered that the smallmouth bass have both a higher incidence of intersex (male fish with eggs) occurrence and a high incidence of skin lesions and large fish kills in the Potomac and James Rivers. Smallmouth bass may be the most sensitive indicator of environmental health in the Chesapeake Bay watershed. The smallmouth bass is a warning that should not be ignored, but the pollution problem they represent are beyond our understanding at this time. More work needs to be done.

Although feminization of male fish has most commonly been associated with exposure to human wastewater-treatment-plant effluent, the prevalence of male smallmouth bass with intersex characteristics is not consistently higher downstream from these point sources than upstream in the areas of the Potomac River watershed that were studied. It is not simply the residue of birth control pills in human waste. However, some additional biomarkers, such as the ratio of gonad weight to body weight and plasma vitellogenin concentrations in female bass, do appear to be adversely affected by the presence of wastewater-treatment plants upstream from the study site, but more is going on.

The sources of the endocrine-disrupting chemicals associated with intersex smallmouth bass appears to be BOTH effluent from wastewater-treatment plants and runoff from agricultural land, animal feeding operations, and urban/suburban land. All impacts of mankind. Other factors, including wastewater-treatment-plant effluent flow, number of animal feeding operations, and number of poultry houses were also associated with an increased intersex severity. Within the Potomac River basin the data showed that the higher the human population density the higher the incidence of intersex in the smallmouth bass. Also, the higher the percentage of agricultural land use density the higher incidence of intersex in smallmouth bass. The data appears to suggest beyond a certain density of agricultural land and/ or human population, the smallmouth bass population is impacted.

The USGS plans to work with the Chesapeake Bay Program to identify the chemicals that are causing the intersex, skin lesions and fish kills. The Chesapeake Bay Program intends to develop toxic contaminant reduction strategies to be added to the Chesapeake Bay TMDL by 2015. The impact on human life and the ecosystem of these and other emerging contaminants is not known, but now is the time to find out the impact from the substance we’ve been allowing to enter the waters of the earth. We need to determine the impact and fate of these micro pollutants before we implement the watershed cleanup plans to make sure we are implementing the right strategies for the health of the entire ecosystem which may include eliminating the use of certain chemicals and other actions.

Endocrine Disruption and What’s in the Potomac River Watershed

Recently in the Susquehanna River in Pennsylvania, smallmouth bass have been found with benign skin tumors. Two skin samples of lesions from fish removed from the river were sent to Dr. Vicki Blazer a mairine biologistand researcher at the U.S. Geological Survey, USGS. Dr. Blazer who received the American Fisheries Society 2010 Publications Award for her article investigating the mortality of fish in the Potomac River basin and is a fish biologist at the West Virginia Science Center studying the impact of contaminants of emerging concern in rivers and streams of the lifecycle and health of fish,  found that one of the samples  tested positive for a type of benign skin tumor. These samples were sent to the USGS because an ongoing collaborative effort between the USGS, the U.S. Fish and Wildlife Service, state agencies in West Virginia, Maryland, and Virginia, and the Potomac Riverkeeper has been studying the impacts of trace contaminants on fish health. Areas of study have been endocrine disruption, immune system impact, cancer/neoplasia promotion, secondary sex characteristics, oxidative damage and behavior. I follow Dr. Blazer’s talks at conferences.

Endocrine disruptors are chemicals that may interfere with the body’s endocrine system and produce adverse developmental, reproductive, neurological, and immune effects in both humans and wildlife. Research evidence suggests that these chemicals, can mimic hormones or interfere with the function of the body’s own hormones. Endocrine disruptors are found in many of the everyday products we use, including some plastic bottles and containers, food can liners, detergents, flame retardants, toys, cosmetics, and pesticides. These hormones and hormone like substances are typically highly soluble in water and are easily transported in the blood. These compounds are of particular concern because they can alter the critical hormonal balances required for proper health and development. The glands that make up the endocrine system are: pituitary gland, thyroid glands, adrenal glands pancreas, ovaries, testies, pineal gland and the thymus.

The marine life work in this area began with the studies of fish kills more than 15 years ago. Preliminary analysis at that time did not find any chemicals or pesticides in concentrations that were sufficient to stress fish and be a cause of the fish kills. Yet there were fish kills. As Dr.Blazer pointed out in a recent conference almost all of our knowledge about concentrations likely to cause a health impact are based on acute toxicity or gross impact such as size. In most cases there are no criteria for sub-lethal effects such as immune modulation or endocrine disruption. Dr. Blazer and others believe that methodology used to detect these chemicals in recent studies may not have been sensitive enough, and may indeed be above the concentration thought to impact these fish. Two examples given by Dr. Blazer at a recent conference were that based on research studies in more than 25 fish species, scientists have suggested that 1 ng/L (parts per trillion) may be the “no effects level” for natural estrogen concentrations on fish. Unfortunately, all the river studies performed in the Potomac River and Shenandoah River passive sampler studies use 1.3 ng/L as the lower detection limit. The detection limit for Potomac and Shenandoah Rivers studies for ethynylesradiol is almost twice the level recently set as the aquatic “no effects” level. Studies along the Potomac and Shenandoah Rivers have only studied smallmouth bass that were found to be intersexed and have measurable amounts of vitellogenin (a protein that is a precursor to egg yoke) in their blood. Vitellogenin is normally only found in the blood of sexually matures egg-laying females, though males typically carry an inactive gene that is “turned on” by the presence of estrogen. Further research is necessary to not only determine if the problem is more widespread geographically and among species, but to identify the mode and mechanism of impact.

Fish health turns out to be a way to track ecosystem health. The smallmouth bass population has been presenting a variety of skin lesions, bacterial, viral and fungil infections, high parasite loads and intersex in normally gonochorist fish ( where embryonic gonad subsequently divides into ovaries or testes). The findings are not at all consistent, but show wide spread biological impact. Scientists like Dr. Blazer are looking to determine if these impacts to fish are being caused by something being put in or released from wastewater treatment plants, farms, or storm water runoff. Until the cause is identified, nothing can be done to stop them and prevent impact to animal and human populations.

Slide taken from Dr. Viki Blazer of USGS presentation

The Potomac fish kills studied by Dr. Blazer and others suggest that there are stressed populations of fish that at some point are overwhelmed by environmental stressors such as increased water temperatures, low dissolved oxygen, excess nutrients, high pH, or chemicals that cause immuno-supression leading to a wide variety of opportunistic infections and the large fish kills. There is increasing evidence that estrogenic chemicals and other endocrine disrupting substance modulate the immune response and disease resistance. In a study of female bass from the Shenandoah River south fork scientists found the BDE (a flame retardant), triclosan (an antibacterial and antifungal agent used in a wide variety of consumer products including toothpaste, mouthwash, deodorant and cleaning supplies) and pesticides had accumulated selectively within the endocrine system with lower concentrations in the brain, skin, kidneys. In talking about the bass, it is reported by Marcia Moore of the Daily Item that Dr. Blazer said, “The good news, for people anyway, is the muscle has the lowest concentration,” indicating that the fish could be eaten. “It’s not such good news for the fish because we’re finding it in the brain, ovaries, kidneys and skin.” The location of the increased concentrations seen in Dr. Blazer’s slide and potential sources of contaminants raises questions about potential human exposure.  

All water on earth is part of the hydraulic cycle and is reused over the course of time. These traces of chemicals have managed to slip through the earth’s natural filtration and some of them through treatment systems to be released into rivers and consumed by humans. Finished and source water (as well as food and beverages) have been found to have low levels of these emerging chemicals, but whether this low level of exposure is bio-accumulating in humans and can cause any health or developments effects is yet unknown. Endocrine disruptors can sometimes affect reproduction, development, and behavior, certainly these impacts on fish is being studied. These potentially endocrine disrupting chemicals come from a variety of sources and have diverse molecular structures. If these chemicals are introduced into water systems from human waste and food, then it is possible that human tissues might also contain detectable levels of contaminants. We might be experiencing subtle population impacts from chemical exposure during fetal and newborn development. Potential human effects from chemical contaminants in tissues of the endocrine system are cancer (particularly breast cancer and testicular cancer), infertility, disorders of sex development, asthma and other immune related syndromes, autism, ADHD, learning and behavioral disorders, diabetes, thyroid disorders, and testicular dysgenesis syndrome (poor semen quality, testis cancer, undescended testis and hypospadias).

The endocrine system of fish bears some similarity to the human endocrine system, but we do not live our lives in the waters of the Potomac. Two million people rely on the Washington Aqueduct for their drinking water and millions of people in other parts of the country drink source water with similar observed occurrences of endocrine disruption. The impact on human life and the ecosystem of these emerging contaminants is not known, but now is the time to find out the impact from the substance we’ve been allowing to enter the waters of the earth. We need to determine the impact and fate of these micro pollutants before we implement the watershed cleanup plans to make sure we are implementing the right strategies for the health of the entire ecosystem which may include eliminating the use of certain chemicals.