Grantee Research Project Results
Final Report: Rapid Indicator for Pollution
EPA Contract Number: EPD07046Title: Rapid Indicator for Pollution
Investigators: Bright, Kelly R.
Small Business: CEDAR Systems
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2007 through August 31, 2007
Project Amount: $69,997
RFA: Small Business Innovation Research (SBIR) - Phase I (2007) RFA Text | Recipients Lists
Research Category: SBIR - Water and Wastewater , Small Business Innovation Research (SBIR)
Description:
CEDAR Systems responds to the U.S. Environmental Protection Agency’s (EPA) need for an inexpensive, convenient, and rapid analytical method for the detection of pollution indicators such as E. coli and enterococci in beach and other recreational waters as a means of identifying risk before exposure has taken place. Currently available tests are far from ideal because they require significant incubation periods (i.e., 18+ hours) to achieve a test result, the methodologies are lengthy and labor intensive, and they require trained personnel and specialized equipment. CEDAR Systems has developed a new Rapid Indicator for Pollution (RIP™) system that detects the presence of E. coli and enterococci in 4 to 6 hours or less, with detection limits at or below EPA guidelines for recreational waters. The system is extremely low risk because it uses reagents that are already established and in everyday use. The RIP™ system detects bacterial enzymes in a very specific reaction, generating unambiguous, easy-to-read results; thus, the test should have extremely low false-positive and false-negative results.
The key innovation in the RIP™ detection system is the inclusion of a microbial concentration step that uses a surface modified, positively charged, high capacity adsorbent. Large volumes of water (e.g., 10 liters) may be passed through a small amount of adsorbent (3 grams) at very high flow rates (e.g., 5 to 30 liters per minute). Following the concentration step, the microbial population and associated enzyme levels are high enough to yield a rapid fluorescence readily observable to the operator after a short incubation period.
Summary/Accomplishments (Outputs/Outcomes):
The RIP™ detection system has yielded promising results during the Phase I performance period regarding the rapid detection of E. coli in water. Using the surface modified adsorbent, CEDAR Systems was able to concentrate the bacteria from large volumes of water with a greater than 99.9 percent recovery on the adsorbent. Without the need for an elution step, the substrate solution then was added to the adsorbent and incubated at 44.5°C (from 4 to 6 hours). After this short incubation, a small volume of the substrate solution was removed from above the adsorbent and evaluated for fluorescence.
The RIP™ detection system can detect 100 cfu E. coli/100 mL in much less time than current detection methods, such as the membrane filtration technique and the Colilert® system (approximately 4 hours versus 24 hours). Although CEDAR Systems has not had as much success using the system to detect enterococci, the RIP™ system also requires less time than the Enterolert® system (< 10 hours versus ≥ 24 hours). By optimizing the protocols, CEDAR Systems can further reduce the amount of time needed to detect both E. coli and enterococci.
Conclusions:
The RIP™ detection system compares favorably to existing EPA-approved methods, such as the membrane filtration technique and the Colilert® system. The RIP™ system can detect smaller concentrations of E. coli in water than the membrane filtration technique because the system concentrates bacteria from much larger volumes of water. This reduces the amount of time necessary to view a positive result. Similarly, the Colilert® system can be used only to sample a total volume of 100 mL, and the RIP™ system detects 100 cfu/100 mL in much less time than the Colilert® system (approximately 4 hours versus 24 hours). In addition, the RIP™ detection system is easily employed in the field.
CEDAR Systems plans to license the RIP™ detection system to existing water treatment companies as part of a commercialization plan; CEDAR Systems has established relationships with several such companies. Two additional markets to target include public beaches and owners of commercial pools and spas (i.e., hotels, country clubs, health clubs). In these large markets, CEDAR Systems’ approach offers the following benefits: (1) greater safety to bathers because a rapid degradation of water quality can be detected quickly, and (2) the RIP™ detection system enables more rapid openings of recreational waters for the enjoyment of bathers.
Supplemental Keywords:
SBIR, small business, RIP™ System, detection of pollution indicators, beaches, bacterial indicators, coastal water, recreational water, drinking water, Escherichia coli, enterococcus, rapid test,, RFA, Scientific Discipline, Water, POLLUTANTS/TOXICS, Environmental Monitoring, Recreational Water, Microorganisms, recreational water monitoring, bacteria, E. coli, recreational beaches, aquatic environments, water quality criteriaThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.