www.epa.gov/research
Technical BRIEF
INNOVATIVE RESEARCH FOR A SUSTAINABLE FUTURE
SAFE AND SUSTAINABLE WATER RESOURCES RESEARCH PROGRAM
Water Systems Research
Resource Water/Water Reuse
Analytical Methods and Monitoring
Water Treatment
Health Impacts
Additional Information and Contacts
Water systems challenged by limited resources, aging infrastructure, shifting demographics, climate change, and
extreme weather events need transformative approaches to meet public health and environmental goals, while
optimizing water treatment and maximizing resource recovery and system energy efficiency. EPA's water systems
research aims to push forward the next generation of technological, engineering, and process advances to
maintain safe and sustainable water resources for humans and the environment, while also augmenting and
improving water resources. EPA's water system efforts focus on breaking down traditional barriers between
drinking water and wastewater (now referred to as resource water) with an emphasis on research that
encompasses the entire water cycle to improve the way we manage water.
Resource Water/Water Reuse
Scientists and engineers in EPA's Office of Research and Development (ORD)
are conducting research on the evaluation of microbial and chemical
contaminants in resource water treatment streams, safe and sustainable
management of waste residuals, and advancing innovative technologies for
water and resource recovery.
Pathogens and Chemicals
Scientists are conducting studies that will thoroughly characterize microbial pathogens and chemical contaminants,
including contaminants of emerging concern (CECs), in resource water through a Regional Applied Research Effort
(RARE) with EPA Region 6. These studies will help to refine risk assessment models for direct potable reuse in Texas
and elsewhere. Building on the RARE effort, ORD researchers will conduct a comprehensive study on microbial
communities and CECs in resource water effluents using high throughput gene sequencing to characterize bacterial,
viral, and protozoan populations. The research effort will also monitor pathogen community dynamics throughout
the treatment systems and provide data on effluent CEC concentrations for traditional wastewater treatment
plants that are considering water reuse.
ORD researchers are also conducting research on antibiotic resistance in resource water. This work will provide data
on the prevalence and human health impacts of antibiotic resistant bacteria (ARB) and the role of treatment on the
U.S. Environmental Protection Agency
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EPA/600/F-16/192 I August 2016
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presence and persistence of ARB in water. The research will attempt to elucidate mechanisms and transfer rates of
antibiotic resistant genes in bacterial populations encountered in resource water. The results of the study might
help us to understand the potential impacts from ARB on human health and the environment in resource water
that is reused or discharged.
Biosolids
Part 503 of the Biosolids Rule that provides guidance on the treatment requirements for land application of
biosolids was most recently updated in 2003. Current research by ORD scientists assesses newer and more accurate
methods for monitoring the microbial characteristics of residuals for land application. This research will provide
support to EPA Program Offices for updating lists of methods for compliance monitoring. EPA researchers are also
examining the transformation and fate of perfluorinated alkyl substances (PFAS) in resource water activated sludge
systems and residuals to better understand the behavior of PFAS in the environment.
Resource Recovery
ORD research on anaerobic membrane bioreactors (AnMBR) examines the efficacy of AnMBR for resource water
treatment for reuse and energy (methane) recovery. This research contains bench-scale experiments on methane
recovery and a Net Zero field study in collaboration with the U.S. Army (Fort Riley, KS) using a pilot-scale AnMBR
treating raw resource water effluents for non-potable reuse.
ORD scientists are also developing and advancing innovative membrane technologies for treating challenging water
sources such as reverse osmosis concentrated brine streams. This research can improve management and lower
costs for inland desalination facilities where brine management is a major contributor to high costs. Additionally
research projects are examining the recovery and reuse of drinking water treatment residuals, bioaccumulation and
recovery of phosphate from resource water, and the development of innovative packaged systems for small-scale
water reuse.
Water Management
ORD plans to integrate resource water/water reuse research results through the development of system-scale
approaches to comprehensively manage water. ORD researchers are currently working with the City of San
Francisco and the State of California to provide better risk assessment models for non-potable (and, in the future,
potable) water reuse at building scales. ORD researchers are also conducting community-scale life cycle
assessments on water resources to improve how we manage all water sources in a given community.
Research Grants
EPA's National Center for Environmental Research (NCER) Science to Achieve Results (STAR) grant program recently
funded water reuse-related research to support the following studies:
• Developing a framework for quantifying microbial risk and sustainability of potable reuse in the United States
• Assessment ofstormwater harvesting via managed aquifer recharge to develop new water supplies in the
arid West: the Salt Lake Valley example.
• Improving water reuse for a much healthier Potomac watershed.
• Enabling adaptive UV and solar-based disinfection systems to reduce the persistence of viral pathogens in
wastewater for sustainable reuse.
• Reclaimed water irrigation: plant accumulation and risks from CECs.
U.S. Environmental Protection Agency
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Analytical Methods and Monitoring
ORD researchers play a critical role in developing analytical methods for
supporting regulatory processes in EPA's Office of Water (OW). Under the 1996
amendments to Safe Drinking Water Act (SDWA), Congress created an
approach for determining which contaminants would become subject to
drinking water standards. The approach includes three components: the
Contaminant Candidate List (CCL), the Unregulated Contaminants Monitoring
Rule (UCMR), and Regulatory Determination. EPA is currently drafting the
fourth CCL. Analytical methods developed by ORD support OW by providing
reliable, robust methods for analyzing contaminants listed on the CCL and standardized methods for water systems
to use for monitoring contaminants under the UCMR.
Algal Toxins and Opportunistic Pathogens Methods
ORD researchers completed Method 544 for six congeners of microcystin and nodularin (cyanobacterial toxins) for
use in the fourth cycle of the UCMR. Researchers continue to work on methods for saxitoxin and related
cyanobacterial neurotoxins. In addition to chemical contaminants, ORD researchers are developing methods for
Legionella and mycobacteria in support of the UCMR. These methods are currently undergoing verification by
external participants in a multi-laboratory study. Lastly, a UCMR method for Toxoplasma gondii (protozoan) oocyst
densities is under development.
Exposure Methods
In addition to research that supports the immediate needs of EPA's Program Offices and Regions, ORD researchers
are looking to the future and developing new analytical methods for exposure risk assessment. ORD researchers
conduct research on the use of salivary immunoassays to determine human exposure to opportunistic pathogens in
drinking water distribution systems and recreational water. Research is also being conducted on the use of MS2
bacteriophage as an indicator organism for determining virus removal in water treatment systems.
Occurrence Studies on CECs, Pathogens, and Disinfection Byproducts
ORD researchers are finalizing one of the most comprehensive occurrence studies on CECs and pathogens in
drinking water treatment systems affected by traditional wastewater plant discharges. ORD collaborated
extensively with scientists in the U.S. Geological Survey for this occurrence study which provided frequency and
concentration ranges for 247 analytes including Pharmaceuticals, hormones metals, PFAS, viruses, bacteria, fungi
and protozoa among other chemicals used in agriculture and commercial settings. The research also assessed
potential human health impacts. This research concluded that for risks from chemicals in treated water was low; for
Pharmaceuticals, 70 percent were never detected in treated drinking water. Mycobacteria were detected in treated
drinking water within the treatment plants which may serve as a source for mycobacteria colonization in
distribution systems. The results also suggested that some of the elemental analytes (silicon, strontium, lithium,
and manganese) will require additional investigation to determine potential human health impacts.
An additional branch of planned research aims to build on occurrence studies and related research on disinfection
byproducts (DBPs) in drinking water systems in an effort to group contaminants for analytical methods and human
exposure studies. This research will lead to the development of new and innovative approaches not only for
prioritizing groups for monitoring and evaluation but also for developing groups for potential Agency action,
including remediation and regulatory consideration.
Sensors and Monitoring
Lastly, ORD researchers are looking forward to the next generation of sensors and monitoring techniques. ORD
scientists are developing sensors based on enzymatic response to contaminants for arsenic and plan to further
develop this technology for other contaminants such as lead. ORD researchers are currently coordinating a sensor
development "challenge" to facilitate the creation of biosensors based on adverse outcomes. These types of
biosensors merge the latest cell-level bioassays with sensors that can potentially provide in-situ signals to warn a
treatment system that there are contaminants in the system that are potentially harmful at the cellular level.
U.S. Environmental Protection Agency
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Water Treatment
Water treatment continues to play a fundamental role in SSWR's research
portfolio. ORD researchers conduct bench-, pilot-, and full-scale investigations
to determine the best available treatment technologies and approaches for a
variety of contaminants. Current research addresses issues such as regulatory
compliance, distribution system corrosion, microbiological contamination, and
challenges presented by emerging contaminants. Research in recent years has
also focused on assisting small- and medium-sized systems in reaching
compliance with current regulations.
Distributions Systems and Premise Plumbing
Distribution system and premise plumbing research plays an increasing role in the SSWR Research Program's
portfolio. In addition to the development of analytical methods for opportunistic pathogens, ORD researchers are
studying the occurrence and behavior of these pathogens in conveyance systems. Research results have been
published on the presence of mycobacteria and Legionella from building taps and shower heads indicating that
mycobacteria are ubiquitous in these systems and Legionella is common. Furthermore, ORD researchers have found
that conditionally rare taxa in distribution systems can rapidly increase in number under favorable conditions.
ORD scientists have been developing microelectrodes to assess the role of biofilms in disinfectant decay on treated
drinking water. The researchers aim to integrate the use of microelectrodes in water systems to optimize
disinfectant levels for maintaining water quality in distributed water.
Lead: Technical Support and the Lead and Copper Rule
Over the past two years, ORD scientists and engineers provided critical technical support to EPA Program Offices
and Regions. During the Flint, Michigan drinking water crisis, ORD engineers provided technical support to the
regional office, state, and utility. ORD installed a pilot-scale pipe testing rig on site in Flint to test optimal water
quality for maintaining disinfectant levels and minimizing lead release. ORD researchers continue this work on lead
pipe samples from other communities with lead service lines.
ORD researchers are also developing a lead sampling protocol for identifying risks from lead pipe in distribution
systems in support of OW's efforts on developing a household action level for lead. In addition to the sampling
protocol, ORD modelers are integrating the Stochastic Human Exposure and Dose Simulation (SHEDS) model with
the Integrated Exposure Uptake Biokinetic Model (IEUBK). Scientists employ the SHEDS-IEUBK model to predict lead
levels in water that will lead to specific blood lead levels in infants, children, and adults. The model accounts for
lead sources other than drinking water and results will be used in creating the household action level.
Algal Toxins
ORD engineers continue to provide technical support and perform research on the removal of cyanotoxins from
source waters. Current research includes treatment optimization for drinking water plants located on Lake Erie and
the impacts from treatment processes, such as permanganate addition, on the release of toxins from intact
cyanobacterial cells.
PFOA/PFOS
ORD engineers also contributed to the development of OW drinking water health advisories for perfluorooctanoic
acid (PFOA) and perfluorooctanesulfonic acid (PFOS) through human health toxicity studies and the identification of
best available technologies for PFOA/PFOS removal.
Small Systems
In addition to research that supports the immediate needs of EPA's Program and Regional Offices, ORD scientists
are developing new, innovative, cost-effective methods for water treatment with an emphasis on small systems,
which are defined in the SDWA as systems that serve fewer than 10,000 people. ORD engineers successfully
installed and operated a biological drinking water treatment system in rural Palo, IA for removing ammonia from
source waters. ORD engineers continue to work with small systems to develop affordable technologies for meeting
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drinking water goals. ORD scientists are assessing the effectiveness of UV systems that utilize light-emitting diodes
(LED). LED-UV systems can potentially reduce costs due to lower energy needs for powering LED systems. ORD
scientists are also working with hospitals and building-scale water treatment systems (consecutive water systems)
to study the impacts of distal water treatment on water quality in buildings.
Ultraviolet Systems for Pathogen Removal
One of the main efforts involving innovative water treatment technology over the past two years has focused on
the use of ultraviolet (UV) light treatment in drinking water and reuse settings. UV technologies are particularly
attractive to small systems due to their ease of operation and effectiveness. However, establishing the proper dose
(or fluence) of UV for inactivating organisms is not straight forward. ORD researchers are currently developing
protocols to test UV systems for effectiveness in treating Adenovirus, which is resistant to many forms of
treatment. Early results suggest that the use of MS2 bacteriophage may serve as an effective, conservative
surrogate to its resistance to UV disinfection. This research also examines the differences in accounting for effective
UV dose differences between low pressure and medium pressure UV treatment systems.
Treatment Database
ORD maintains and updates EPA's Drinking Water Treatability Database which provides utilities with
recommendations on effective technologies for removing a wide range of chemical, microbiological, and
radiological contaminants. The treatability database will be merged with OW cost models to provide stakeholders
the ability to include cost factors when selecting treatment processes, iaspub.epa.gov/tdb/pages/general/about.do
Technology Cluster
Many of the innovative water treatment technology projects are supported by the Water Technology Innovation
Cluster (WTIC) program. The WTIC seeks to identify new and innovative water treatment technologies and barriers
in the acceptance of new technologies. It will be critical to accelerate the acceptance of new technologies as
pressures on water resources increase.
Research Grants
NCER funding through the STAR and National Priorities grants has supported to following treatment-related
research:
1. Studies on advancing public health protection through water infrastructure sustainability
• Biofilm behavior within distribution systems.
• Development of real-time mobile sensor device for monitoring distribution system water quality.
• Development and demonstration of a hybrid ion exchange catalytic treatment system for nitrate removal
from drinking water.
• Development of nanoscale fibers for treating waterborne contaminants in small drinking water systems.
• Case studies of small systems in rural Missouri for controlling DBP levels in finished water.
1. National small systems drinking water research centers
• Design of Risk Reducing, Innovative Implementable Small System Knowledge (DeRISK) Center
• Water Innovation Network for Sustainable Small Systems (WINSSS)
2. Distribution systems studies
• National Priorities: Impacts of water conservation on water quality in premise plumbing and water
distribution systems
3. Drought resiliency studies
• Consequences of watershed management practices against wildfire on the exports of dissolved organic
matter from forested watersheds and associated biogeochemical processes and impacts on water supplies.
• Innovative methods for improving water management by reducing risks from inadequate drought
preparedness, including pre-drought planning and emergency response.
U.S. Environmental Protection Agency
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Health Impacts
ORD's SSWR researchers are studying human health risks posed by
contaminants (microbial, chemical, and radiological) associated with water
systems, including those contaminants found in finished water that are either
not removed by treatment, are formed or altered during water treatment and
then later affected by residence time in water systems, or those impacted by
wastewater treatment processes. Research in this area will improve estimates
of human health risk and inform risk management.
Impacts of Disinfection Byproducts
ORD scientists continue to provide immediate support to Program Office decisions on water contaminants through
technical support for the six-year DBP rule process. Health effects research currently focuses on DBP (regulated and
non-regulated) consequences to human health. ORD researchers are re-examining regulated DBPs effects on
bladder cancer. They are also performing studies on DBP exposure and colon cancer using human colonocyte
cytotoxicity assays. These cellular assays afford a higher throughput than tradition toxicity methods. This work will
eventually use the assays for testing individual DBPs and environmentally realistic mixtures of DBPs.
ORD scientists are using physiologically-based pharmacokinetic (PBPK) models for assessing human health impacts
from DBPs. The models emphasize the need to consider alternative (to ingestion) exposure routes such as dermal
and inhalation exposure which may significantly contribute to internal doses for internal organs. Health impacts
research also currently includes studies on integrated exposure assessments that focus on varying halogen (e.g.
bromine, iodine) concentrations' impacts on DBP formation and the toxicity of the mixtures formed during
chlorination and chloramination.
Toxicity Screening
ORD researchers are also looking to the future in developing innovative toxicity screening methods that involve
tiered screening approaches that couple bioassays with analytical chemistry for effects-directed analysis. In
addition to bioassay methods, immunological salivary assays can be used to screen for exposure to contaminants in
drinking water. Research is also being conducted on in-vivo developmental toxicity screening methods for water
contaminants and effects on pregnancy disruption and ocular development. ORD research will fill in knowledge
gaps in risk from aerosolization of waterborne pathogens in order to gain a more realistic understanding of internal
doses from sources other than ingestion. ORD researchers are conducting studies to compare the toxic effects of
different microcystin congeners in freshwaters of the U.S.
Waterborne Diseases
ORD researchers currently collaborate with scientists from the Centers for Disease Control and Prevention to
develop methods to characterize waterborne diseases through outbreak surveillance and identify waterborne
diseases associated with distribution systems. Lastly, ORD is examining the role of waterborne and environmental
pathogens as triggers for Type 1 diabetes.
Additional Information
EPA's Safe and Sustainable Water Resource Research: epa.gov/water-research
Contacts
Michelle Latham, latham.michellef
U.S. Environmental Protection Agency
Office of Research and Development
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