What the research shows about NDMA and potable reuse.
This library brings together peer-reviewed research, government toxicology assessments, treatment studies, analytical methods and technical guidance relevant to NDMA in drinking water and potable reuse systems. It provides the scientific context for reviewing the Wichita Falls historical record and evaluating current monitoring and treatment.
Different sources document different parts of the science.
The materials collected here include several types of scientific evidence. Each contributes to understanding NDMA formation, treatment performance, monitoring, occurrence and potential health risk.
Peer-reviewed research
Journal studies examine NDMA formation, treatment behavior, membrane rejection, ultraviolet destruction, precursor chemistry and changes within water systems.
Government assessments
EPA, ATSDR, California OEHHA and other agencies evaluate toxicology, health risk, drinking-water occurrence and analytical methods.
Technical guidance
Potable-reuse guidance and technical reports describe treatment trains, monitoring practices, operational considerations and lessons from full-scale systems.
Browse by subject
Research is grouped by the scientific issues most relevant to understanding NDMA behavior in treated drinking water and potable reuse systems.
NDMA Formation & Precursors
Research on chloramination, precursors, wastewater influence and the conditions associated with NDMA formation.
Review formation research →Reverse Osmosis
Studies examining NDMA passage, membrane rejection, operating conditions and precursor removal.
Review RO research →UV Treatment & AOP
Research concerning NDMA photolysis, ultraviolet fluence, UV-based advanced oxidation and treatment performance.
Review UV research →Potable Reuse
Studies and technical guidance involving indirect and direct potable reuse treatment trains and NDMA monitoring.
Review reuse research →Distribution & Post-Treatment
Research examining NDMA formation after treatment, chloramination, storage and transmission through water systems.
Review distribution research →Health & Toxicology
Government toxicology assessments, health-based values and scientific reviews concerning NDMA exposure.
Review health resources →NDMA formation and precursors
NDMA can form during drinking-water and wastewater treatment when precursor compounds interact with disinfectants and other treatment conditions. Chloramination has received particular attention in the scientific literature.
Measuring NDMA at one point in a treatment process does not establish its concentration at every other point. Research has documented precursor loading, formation during treatment and continued formation after water enters storage and distribution systems.
Formation, precursors, control, and occurrence of nitrosamines in drinking water: a review
Major review of NDMA occurrence, precursor chemistry, chloramination, formation mechanisms and treatment approaches in drinking-water systems.
NDMA formation during drinking water treatment: A multivariate analysis of factors influencing formation
Analysis of treatment plants in the United States and Canada examining treatment and water-quality factors associated with NDMA in finished and distributed water.
The role of chloramine species in NDMA formation
Research examining monochloramine, dichloramine, precursor compounds and chemical conditions involved in NDMA formation.
NDMA and its precursors in water and wastewater: A review on formation and removal
Broad review covering wastewater-derived precursors, chloramination, potable reuse, ultraviolet treatment and other NDMA control strategies.
Reverse osmosis and NDMA
Reverse osmosis is widely used in advanced potable-reuse treatment. NDMA presents a particular treatment challenge because it is a small, neutral molecule and its rejection can vary with membrane and operating conditions.
RO performance for larger contaminants does not establish NDMA removal. Full-scale and laboratory studies have reported variable NDMA rejection depending on membranes, temperature, recovery and other operating conditions.
Evaluating the impacts of membrane type, coating, fouling, chemical properties and water chemistry on reverse osmosis rejection of nitrosamines
Laboratory research examining how membrane characteristics, water chemistry and fouling influence rejection of NDMA and other nitrosamines.
NDMA removal by reverse osmosis and UV treatment
Study of an advanced wastewater treatment facility using microfiltration, reverse osmosis and ultraviolet-based treatment, with NDMA measured throughout the process.
N-nitrosamine rejection by reverse osmosis membranes: a full-scale study
Full-scale evaluation of nitrosamine rejection across multiple RO systems and operating conditions.
Influence of reverse osmosis membrane age on rejection of NDMA precursors and formation of NDMA in finished water
Full-scale potable-reuse study examining RO membrane age, precursor rejection and subsequent NDMA formation after advanced treatment.
Ultraviolet treatment and advanced oxidation
NDMA absorbs ultraviolet light and can be destroyed through UV photolysis. Research on potable reuse has examined treatment fluence, UV-based advanced oxidation and interactions with water chemistry.
UV used for microbial disinfection and UV used for chemical contaminant destruction serve different treatment objectives. Research on NDMA treatment commonly evaluates UV exposure substantially beyond ordinary disinfection requirements.
NDMA removal by reverse osmosis and UV treatment
Research measuring NDMA through an advanced wastewater treatment train and evaluating removal through both reverse osmosis and ultraviolet treatment.
NDMA and its precursors in water and wastewater: formation and removal
Review of NDMA treatment literature, including ultraviolet photolysis and the higher UV fluence generally associated with chemical removal compared with disinfection.
UV-chlorine advanced oxidation for potable water reuse
Review of UV-chlorine advanced oxidation in potable reuse, including the influence of ammonia, chloramines and treatment chemistry.
View the 2015 Garver pilot records →
NDMA in potable reuse systems
Municipal wastewater can contain NDMA and NDMA precursor compounds. Potable-reuse research therefore addresses source control, treatment, monitoring, formation potential and post-treatment water quality.
Potable reuse combines multiple treatment processes. Evaluating NDMA requires looking across the treatment train because concentrations and precursor behavior can change from one treatment step to the next.
NDMA formation at an indirect potable reuse facility
Study examining NDMA behavior through treatment processes at an indirect potable reuse facility, including RO, UV/H₂O₂, chloramination and other treatment steps.
N-nitrosamines and halogenated disinfection byproducts in U.S. full advanced treatment trains for potable reuse
Research measuring nitrosamines and other disinfection byproducts across five U.S. potable-reuse treatment trains.
EPA Potable Reuse Compendium
Federal technical reference covering IPR and DPR, treatment technologies, chemical constituents, monitoring, risk, regulation and U.S. case studies.
NDMA soft-sensors for potable reuse: A model development study
Recent potable-reuse research examining approaches to improve NDMA monitoring where continuous direct measurement is not currently available.
View Wichita Falls IPR records →
Distribution systems and post-treatment formation
Water continues to undergo chemical and biological changes after it leaves a treatment plant. Research has examined NDMA formation during storage, transmission and distribution.
Finished-water sampling at the treatment plant and sampling farther into a distribution system provide different information. Residence time, chloramine chemistry, nitrification and remaining precursors can influence downstream conditions.
Impact of nitrification on formation of N-nitrosamines within distribution system storage facilities
Study of chloraminated drinking-water storage facilities examining nitrification, nitrosamine precursors and NDMA formation within distribution infrastructure.
NDMA formation during drinking water treatment
Multi-plant research evaluating factors associated with NDMA measured in finished and distribution-system water.
NDMA precursor rejection and formation in finished water after full advanced treatment
Full-scale research documented NDMA formation in finished potable-reuse water during transmission after advanced treatment.
Health and toxicology
Government agencies have evaluated NDMA toxicology, cancer risk and drinking-water exposure. Health-based values and regulatory standards serve different purposes and may be developed under different risk frameworks.
California OEHHA released a second draft of its proposed updated Public Health Goal for NDMA in drinking water on September 11, 2026. The updated assessment is currently undergoing the public review process.
Proposed Updated Public Health Goal for NDMA
California OEHHA's current scientific assessment of NDMA in drinking water, including toxicology, risk assessment and the proposed updated health-based goal.
Nitrosamines in drinking water
California drinking-water reference page providing notification levels, response levels and health-based information for NDMA and other nitrosamines.
Toxicological Profile for N-Nitrosodimethylamine
Comprehensive federal review of toxicological and epidemiological information concerning NDMA exposure and health effects.
EPA IRIS assessment for N-Nitrosodimethylamine
EPA Integrated Risk Information System entry containing the agency's cancer assessment and quantitative carcinogenic risk information for NDMA.
Analytical methods and drinking-water monitoring
Reliable NDMA evaluation depends on analytical methods capable of measuring concentrations in the low nanogram-per-liter range. Federal drinking-water programs provide important reference methods and occurrence data.
EPA Method 521
EPA analytical method for determination of nitrosamines in drinking water using solid-phase extraction and tandem mass spectrometry.
View EPA Method 521 →Unregulated Contaminant Monitoring Rule 2
EPA's second UCMR monitoring cycle included NDMA and other nitrosamines and produced national occurrence data from public water systems.
View UCMR 2 →The science provides context for the historical record.
The research documents how NDMA can form, how it behaves during treatment, the limitations of reverse osmosis for NDMA removal, the UV exposure used for NDMA destruction, the potential for post-treatment formation and the methods used to measure NDMA in drinking water.
Applying that science to Wichita Falls requires system-specific evidence. The local record includes laboratory results, treatment configuration, operating information, chemical treatment, regulatory correspondence and monitoring records.
Where measurements were not collected during the 2014–2015 DPR operation, scientific literature cannot recreate those historical concentrations. It can show why those measurements would have mattered and provide context for evaluating the monitoring and treatment decisions documented in the record.
Compare the science with the source documents.
Review the Wichita Falls laboratory results, engineering materials, regulatory correspondence, monitoring history and project chronology alongside the scientific literature collected here.