Impact/Purpose:

The objective of this task is to develop a rapid turnaround method for the determination of Disinfection By-Product formation potential (DBP-FP) and the development of the instrumentation system necessary for the detection of DBP-FP.

Description:

EPA requires drinking water utilities to monitor source water to determine the need for treatment to remove the precursors (natural organic matter {NOM}) of disinfection by-products (DBPs). Currently, drinking water utilities use total organic carbon (TOC), dissolved organic carbon (DOC), and specific UV absorbance (SUVA) for monitoring purposes. It is believed that knowing these parameters will allow water treatment plants to economically enhance the treatment of raw water to reduce DBPs. It is also believed that source water with a low SUVA value ( SUVA <2.0 L/mg-m) does not require treatment. However, research by the United States Geological Survey (USGS) has shown that this assumption can be erroneous and that some of the source waters that have low TOC and SUVA could be highly reactive and form DBPs. Under the current Stage I D/DBP Rule, these waters would not be treated. Therefore, a better indicator (other than TOC/SUVA) of the disinfection by-product-formation potential (DBP-FP) is needed. Thus, the objective of this task is to develop a rapid turnaround method for the determination of DBP-FP and the development of the instrumentation system necessary for the detection of DBP-FP. The new methodology/instrumentation will provide a rapid means for monitoring DBP-FP, thus providing water treatment plants with the ability to alter engineering to reduce DBPs in finished water. In turn, the proposed development of DBP-FP methodology/instrumentation will impact EPA monitoring programs by providing a more accurate analytical monitoring tool/method for optimizing removal of DBP precursors. The drinking water utilities, and their customers will benefit by improved treatment efficiencies and reduced cost of treatment. In addition, the DBP-FP instrumentation can enhance drinking water security by providing real time monitoring capabilities within the utility's distribution system. An increase of DBP-FP in the distribution system, as compared to the source water DBP-FP, would alert the plant operator that a biological or chemical agent has contaminated the system. The utility would have an early warning of the contamination and could take corrective action to avert a potential crisis by diverting flow within the distribution system to remove or isolate the contaminated drinking water and/or by alerting the consumer of the potential danger of the contaminated drinking water. The DBP-FP monitoring system would provide a safe-guard for the distribution system and long term protection of human health by the reduction of DBPs.

Record Details:

Record Type:PROJECT

Start Date:10/01/2002

Projected Completion Date:09/01/2007

OMB Category:Other

Record ID: 19933

Show Additional Record Data

Project Information:

Progress :Ongoing discussions are being held with EPA's Technology Transfer Coordinator. An Opportunity Assessment has already been conducted by the National Technology Transfer Center which included both technology and market assessments. There was considerable interest from potential cooperators and end users. Preparation of a U.S. Environmental Protection Agency, Employee Report of Invention, has begun and will be submitted in FY05.

The quality assurance project plan (QAPP) has been submitted and approved.

Laboratory instruments and equipment are in the process of being procured (FY05).

Relevance :The Government's primary mission is to protect human health. In this case, by reducing exposure to chemical contaminants via drinking water. The EPA Office of Water (OW) and the Office of Ground Water and Drinking Water (OGWDW) must have a method that can meet the monitoring requirements proposed in the Stage 1 and Stage 2 Disinfectants/ Disinfection By-Products (D/DBP) Rule. The Disinfectants/Disinfection By-Product Rule requires the implementation of enhanced coagulation as a control strategy for the removal of natural organic matter from source water. This should effectively decrease the formation of all disinfection by-products (DBPs) that are formed when a disinfectant is added to finished water. The proposed Rule requires a percent of the TOC to be removed that is based on the influent TOC concentration and the alkalinity of the water (40CFR Part 9, Section 141.135 in the Rule - Federal Register). The TOC measurement is used to determine when the regulated utility will be required to use enhanced treatment on the source water prior to the disinfection step. The TOC measurement has historically been considered to be a good indicator of the potential amount of DBPs that can be produced from a source water containing organic precursor matter, usually fulvic and humic acids. TOC measurements were selected as a practical method for estimating DBPs because it would be unmanageable to try to establish compliance monitoring for all of the known DBPs. However, there is recent concern that the TOC analytical methods may overestimate the need for treatment, thus increasing the cost of water treatment. Of further concern, is the underestimation of the need for treatment using the TOC measurement. Some utilities may have high turbidity and high organic particulates in their source water which may account for a significant portion of the TOC measurement. The particulates and turbidity are easily removed and may provide a reduction in TOC to compliant levels without further treatment. However, the DOC remaining in the source water would still be disinfected and result in high levels of DBPs in the treated drinking water. Therefore, in this case, the TOC measurement provides an unintended "loop hole" for the water utility, as the DBPs are not removed or minimized. Likewise, research by the United States Geological Survey has shown that some source waters that have low TOC and SUVA could be highly reactive and form DBPs (1)(2) .

It is important that the treatment cost be optimized by selecting an appropriate analytical method for monitoring the utility that does not overestimate or underestimate the treatment for the removal of DBP precursors. The research proposed in this task should reduce the TOC/SUVA error associated with predicting the need for enhanced coagulation. The DBP-FP (method) approach may result in substantial savings in treatment costs for some utilities with a more efficient control and removal of DBP(s). The DBP-FP instrumentation system will be developed under the CRADA/Patent Licensing Agreements, as per the Federal Technology Transfer Act (FTTA). In turn, the proposed development of the DBP-FP methodology/instrumentation will impact EPA monitoring programs by providing a better analytical monitoring tool/method for the removal of DBP precursors. The drinking water utilities, and their customers will benefit by improved treatment efficiencies, reduced cost of treatment and protection of human health by the reduction of DBPs.

Clients :Office of Ground Water and Drinking Water (Pat Fair)

Research Component :M/DBP (DBP)

Risk Paradigm :EXPOSURE

Project IDs:

ID Code :none

Project type :ORD-DW Plan

ID Code :12507

Project type :OMIS