Our Work

Water Defense is rooted in the belief that access to clean safe water is a fundamental human right. Our work aims to protect this right for everyone regardless of income level, race, national origin, beliefs, or location. We prioritize unbiased data collection and seek to leverage that information to protect aquatic resources and equal access to clean water.

Water Defense conducts water testing activities throughout the United States, gathering data and raising public awareness about the major issues affecting water and public health. We respond to water contamination events by deploying an investigative team on the ground to collect water samples and document contamination.

We collect water samples using two different methods. The first is a traditional “grab” sample, in which pre-cleaned, EPA certified VOC/SVOC[1] and general sampling containers, approved for metal sampling, are filled with water, sealed, and labeled, and sent to an accredited independent laboratory with proper chain of custody documentation. The second water sampling method utilizes a new technology called the “WaterBug.” The WaterBug was designed to collect an integrated and cumulative sample of contaminated water over time. We believe that this technology serves to average out the episodic changes in water contamination concentrations inherent in many bodies of water such as lakes, rivers, streams, oceans, as well as municipal water supplies, irrigation systems, and in premise plumbing fixtures. The WaterBug was also designed to detect the presence of contamination that might otherwise remain undetected by traditional grab sampling methods. Water Defense uses the WaterBug in concert with traditional grab sampling methodology in order to generate a more detailed and comprehensive measurement of water contamination.

Once our investigative team has collected water samples, documented our sampling methodology and completed chain-of-custody reports, the water samples are transported to ALS Environmental, an independent and accredited water-testing laboratory. ALS relies on well-established and validated testing methodologies, including those recommended by the US Environmental Protection Agency (EPA). Laboratory testing protocols of WaterBug samples are designed by Water Defense to ensure the reliability of data produced and minimize variability across samples. For more information about ALS testing of WaterBug samples, please visit our page on Lab Testing of WaterBug Samples.

Upon receipt of the analytical reports of our tested samples from the laboratory, we work with our scientific advisors to review, interpret and release the data to the community and other stakeholders. Water Defense is proud to work with a highly-trained and multidisciplinary group of scientists with varied expertise. While community-based citizen-scientists provide a critical role for making science happen, we also recognize the value of traditionally-educated science professionals for guiding experimental design and data interpretation. Water Defense prioritizes transparency and the public release of unadulterated and complete lab reports, along with scientifically-vetted statements concerning potential public health and environmental impacts. We continually offer an invitation for individuals and organizations to join us at any stage of our work, whether it be collecting samples, interpretation of laboratory reports, or public dissemination of information.

Our Work in Flint

Our work in Flint began in January 2016, when we made our first trip to the city to investigate the on-going water contamination crisis. The goal of our first trip was to conduct a preliminary investigation into the nature of the crisis, better understand any historical contamination, and identify any factors that existed or continue to exist that have impacted the local water supply. Before we arrived in Flint, we conducted our standard pre-investigation research to inform our sampling locations and working protocols. This research included a time-line of events that led to the water contamination, as well as responsive actions taken by the state and local governments.

Despite the fact that by January 2016, the City of Flint was no longer using the Flint River to supply municipal drinking water, we took baseline samples from the river to determine what physical-chemical factors may have been present that aided in the observed pipe corrosion. Sampling of the Flint River was also performed to gain an independent evaluation of contributing historical factors and contamination levels to better understand corrosion potential and background contamination that could be considered or ruled out from a risk characterization standpoint. Water Defense sought to determine, among other things, whether there were sources of metals (particularly lead) still present in the previously-used source water. Those data collected from the Flint River provided a reference for the corrosion and contamination existing throughout Flint. Water Defense has since used the data gathered to inform our on-going work in Flint. Laboratory findings from these studies can be found in the following link: Flint River Baseline 1602002 Report

As our work progressed in the following weeks and months, Water Defense continued to document the presence of various water contaminants at concentrations that suggested potential health concerns. For example, using a grab sample, we documented bathwater that contained 16 parts per billion (ppb) of lead, which exceeds the EPA Action Level of 15 ppb, at which federal regulators require a water system to take action to protect public health.

Water Defense has also been engaged in testing the effectiveness of filtration technology produced by an independent local Flint-based company, as part of Scott’s work on the ground with the United Association of Plumbers, Pipefitters, Sprinklerfitters, and Service Technicians (“UA”) known in Flint as the UA Local 370 Plumbers’ Union. This work was undertaken to evaluate the utility of filtration systems in order to provide for the protection of the Flint community, and neither Scott nor Water Defense has received any financial payment for this work. No technology or product developed by Water Defense or invented by Scott Smith will be evaluated or considered for use in Flint as a filtration product. The testing results for this work can be found in at Flint House #6 (2nd visit) 1603753 Report and Flint House #2 (2nd visit).

Showering in Flint Water

Flint residents have long known about the dangers of drinking unfiltered municipal water. Because they have been informed that the water is unsafe for drinking and preparing food, they are able to protect themselves from further exposure to lead from drinking water. However, based on community comments regarding skin irritation, rashes, hair loss, and other health issues, Water Defense became concerned that residents may not have been properly informed of the potential risks of showering in unfiltered Flint water. Laboratory testing of samples collected revealed presence of contaminants, some of which have the ability to volatize into the air and be inhaled, or be dermally absorbed through the skin.

Our findings and input from our scientific support team informed our decision to question statements coming from the State of Michigan Department of Environmental Quality, which assured residents that it was safe to shower in Flint water. Consequently, we began testing water heaters and hot water in showers utilizing both sampling methods identified above in an attempt to ascertain which contaminants exist that present a potential risk for exposure via inhalation or dermal absorption.

Our testing of bath and shower water throughout Flint revealed various chemicals known as disinfection by-products (DBPs), which include trihalomethanes (THMs) such as chloroform. These contaminants are formed when disinfectants such as chlorine, which are used to control microbial contamination, react with naturally-occurring organic and inorganic matter in water.

Chlorine is a well-known disinfectant used around the world to keep water systems safe from microbial contamination. The organic matter that it reacts with exists naturally in source water. The presence of chloroform and other DBPs in tap water is an expected trade-off from the necessity of using chlorine as a disinfectant. Our concern was based not on the mere presence of DBPs, but on the levels at which they were occurring and the potential human exposure pathways that were not being addressed.

Laboratory reports on grab samples we collected from baths and showers throughout Flint showed levels of chloroform concentrations ranging from 0 to 38 ppb.[2] Although these levels are below the existing EPA Maximum Contaminant Level (MCL) of 80 ppb for total trihalomethanes, we believe this federal legal limit should be lowered to well below 80 ppb. The significant toxicity of some THMs and other less-studied DBPs have been documented by scientists throughout the world, and in the last twenty years the evidence implicating THMs in serious disorders has mounted: A collection of peer-reviewed scientific literature has shown adverse health impacts such as bladder cancer,[3] reproductive risks, still births, and adverse developmental effects[4] associated with exposure to THM concentrations between 20 and 50 ppb. Furthermore, the EPA MCL for THMs was created under the assumption that the main route of exposure to these chemicals was via drinking water. Our research, and input from our science support team, has raised the point that drinking may not be the most important route of exposure. Numerous studies have shown that showering and bathing are important routes of exposure, primarily via inhalation, for THMs and may actually contribute more to total exposure than drinking water.[5] While there are hundreds of DBPs that are currently known to exist with new compounds continually emerging, only 11 DBPs are currently regulated.[6] Emerging DBPs have created a steadily growing regulatory gap and implicate potentially unaddressed public health concerns.[7]

While there is no doubt that refraining from showering/bathing will cause adverse health impacts that are of concern and pose their own immediate and long-term health risks, there are other options that are hygienic and could reduce or possibly mitigate exposure to contamination. Showering in cold or cool water has been shown to reduce the amount of aerosolized contaminants dramatically.[8] Additionally, taking a hot bath as opposed to showering in hot water reduces the amount of aerosolized particulates and volatiles released into the air. Moreover, keeping the windows and bathroom door open while showering increases the ventilation and thus reduces any potential exposure. A good option for residents who believe they are at-risk of suffering from contaminant exposure is to take luke-warm (or even cold) baths in a well ventilated area.

Water Defense believes that each individual and family should make their own personal choice regarding potential risk and response to contaminant exposure. We want the community of Flint to know that when using Flint water to shower, there are some considerations they should be aware of in order to make a personal decision. We believe that the residents of Flint have a right to reliable and complete information to inform these personal decisions. By providing the residents of Flint with this information, Water Defense has empowered the community to make their own personal decisions for themselves and their families which are informed by reliable data and published scientific research. We stand by our work and will continue to support the people of Flint as they pursue their fundamental right to clean safe water.


[1] VOCs stand for Volatile Organic Compound; SVOC stands for Semi-volatile Organic Compound.

[2] WaterBug samples collected from baths and showers throughout Flint showed levels of chloroform concentrations ranging from 0 to 94 ppb. We are continuing to evaluate the WaterBug technology and the implications of this data. For more information please see our frequently asked questions and answers page.

[3] Costet N, Villanueva CM, Jaakola JJ, Kogevinas M, Cantor KP, King WD, Lynch CF, Nieuwenhuijsen MJ, Cordier S. 2011. Water Disinfection By-products and Bladder Cancer: Is there a European Specificity? A pooled and meta-analysis of European case-control studies, Occup. Environ. Med. 68(5): 379-85; Villanueva C, Cantor K, Grimalt J, Malats N, Silverman D, Tardon A, et al. 2007. Bladder Cancer and Exposure to Disinfection By-products through Ingestion, Bathing, Showering, and Swimming Pools, American Journal of Epidemiology 165(2): 148-56; Chang C, Ho S, Wang L and Yang C. 2007. Bladder Cancer in Taiwan: Relationship to Trihalomethane Concentrations Present in Drinking Water Supplies, Journal of Toxicology & Environmental Health Part A 70(20): 1752-7; Cantor K, Villanueva CM, Silverman DT, Figueroa JD, Real FX, Garcia-Closas M, et al. 2010. Polymorphisms in GSTT1, GSTZ1, and CYP2E1, Disinfection Byproducts and Risk of Bladder Cancer in Spain, Environmental Health Perspectives 118(11): 1545:50.

[4] Summerhayes RJ, Morgan GG, Edwards HP, Lincoln D, Earnest A, Rahman B, Beard JR. 2012. Exposure to Trihalomethanes in Drinking Water and Small-For-Gestational-Age Births, Epidemiology 23(1): 15-22; Levallois P, Gingras S, Marcoux S, Legay C, Catto C, Rodriguez M, Tardif R. 2012. Maternal Exposure to Drinking-Water Chlorination By-Products and Small-For-Gestational-Age Neonates, Epidemiology. 23(2): 267-76; Hwang BF, Jaakola JJ. 2012. Risk of Stillbirth in the Relation to Water Disinfection By-products: a population-based case control study in Taiwan, PLoS One. 7(3):e33949; Hoffman CS, Mendola P, Savitz DA, Herring AH, Loomis D, Hartmann KE, Singer PC, Weinberg HS, Olshan AF. 2008. Drinking Water Disinfection By-product Exposure and Fetal Growth, Epidemiology 19(5): 729-37; Toledano MB, Nieuwenhuijsen MJ, Best N, Whitaker H, Hambly P, de Hoogh C, Fawell J, Jarup L, Elliot P. 2005. Relation of Trihalomethane Concentrations in Public Water Supplies to Still Birth and Birth Weight in Three Water Regions in England, Environmental Health Perspectives 113(2):225-32; Wright JM, Schwartz J, Dockery DW. 2003. Effect of Trihalomethane Exposure on Fetal Development, Occup. Environ. Med. 60(3): 173-80; Bove F, Shim Y, Zeitz P. 2002. Drinking Water Contaminants and Adverse Pregnancy Outcomes: a review, Environmental Health Perspectives 110 (Suppl 1): 61-74.

[5] Backer LC, Ashley DL, Bonin MA, Cardinali FL, Kieszak SM, Wooten JV. 2000. Household Exposures to Drinking Water Disinfection By-products: whole blood trihalomethane levels, Journal of Exposure Analysis & Environmental Epidemiology 10(4): 321-6; Kerger BD, Schmidt CE, Paustenbach, DJ. 2000. Assessment of Airbourne Exposure to Trihalomethanes from Tap Water in Residential Showers and Baths, Risk Analysis 20(5): 637-51; OEHHA. 2004. Evidence on the Development and Reproductive Toxicity of Chloroform, California Office of Environmental Health Hazard Assessment; Xu X, Weisel CP. 2003. Inhalation Exposure to Haloacetic Acids and Haloketones during Showering, Environmental Science & Technology 37(3): 569-76; Nuckols JR, Ashley DL, Lyu D, Gordon, SM, Hinckley AF, Singer P. 2005. Influence of Tap Water Quality and Household Water Use Activities on Indoor Air and Internal Dose Levels of Trihalomethanes, Environmental Health Perspectives 113(7): 863-70.

[6] Regulated Disinfection Byproducts include four trihalomethanes (chloroform, dibromochloromethane, bromodichloromethane, and bromoform), five haloacetic acids (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid), bromate and chlorite.

[7] Richardson SD, Plewa MJ, Wagner ED, Schoeny R, Demarini DM. 2007. Occurrence, Genotoxicity, and Carcinogenicity of Regulated and Emerging Disinfection By-products in Drinking Water: a review and roadmap for research, Mutation Research 636(1-3): 178-242.

[8] Id.

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