Failure of onsite wastewater systems: definitions, practices, and public health protection

1. Figure 2. Causal Loop Diagrams and applicable Archetypes: Shifting the Burden – Mental Model Local/County Health Department (LHD) started to install monitoring wells adjacent to OWW systems LHD: We want to know if people who are served with OWW systems and those who have private wells are not exposed to contaminants from wastewater B 1 The problem of defining onsite wastewater systems failure at local level will continue over the long run. Signs of an improved definition will be seen eventually. Problem Symptom Initial findings indicate that OWW systems might be contaminating groundwater OWW Rules  Treatment failure included in rules (GA) and not included (NC). Monitoring OWW systems performance is difficult R Quick Fixes Unforeseen adversaries who resist change; their interests were affected 3 Current practices for remediation of failing OWW systems do not focus on systems’ performance. Failing systems are replaced or repaired, but the potential for groundwater contamination remains. B 2 State Rules changed as result of research and development of methodology for OWW systemsmonitoring performance. Implementation phase started 4 Long Term Solutions Acceptability of a new definition of failure for OWW systems to be based on performance is expected to grow. Time Failure of onsite wastewater systems: definitions, practices, and public health protection Max A. Zarate-Bermudez, MS MPH PhD* Assistant Professor, Environmental Health and Safety Program, East Carolina University, Greenville, NC 27858 *Currently at the Environmental Health Services Branch, Centers for Disease Control and Prevention - NCEH; Atlanta, GA 30341 LOGO LOGO BACKGROUND METHODOLOGY RESULTS • Georgia and Florida, not North Carolina, include performance as part of their OWW systems failure definition in the states’ Rules.1-3 • Potential impact of OWW systems on public health: >26 million US housing units with OWW systems4 (now ~33% of new homes).5 Much houses having an OWW system have a private well for drinking water (DW). • Percentage of WBDOs associated with DW from private wells fluctuated: 46% 1999-2000;6 29% 2001-2002;7 16.7% 2003-2004;8 and 30% 2005-2006.9 US DW systems could be vulnerable to contamination. • Chemical and microbiological contamination of water associated with OWW systems.10-12 Conventional systems linked to disease causation.10,11 • Procedures to determine failure, remediation of systems that failed, and measures to minimize failure are similar in GA and NC; those are clearly described by states’ Rules. • Funding is the main limitation reported  daily work overload. • The need for reviewing the definition of OWW systems failure is growing. • It is important to develop and implement a methodology for monitoring performance of OWW systems. Current definitions of failure or malfunction of onsite wastewater (OWW) systems at the state level may not be helping to protect public health. Failure of these systems is defined as the surfacing of wastewater on the dispersion field, ponding, and wastewater backup to the house. However, a possibility exists that systems not failing under those definitions may be contaminating groundwater and putting public health at risk. The number of waterborne disease outbreaks (WBDOs) associated with drinking water from private or non-community wells fluctuated between 1999 and 2006. Information on the definitions and practices of OWW systems failure from county health departments in Georgia and North Carolina was gathered. Also, a literature review in relation to the potential impact of OWW systems on public health was conducted. A summary of the information gathered and its interpretation is described below. • Project period: July 2008 to January 2009. • Research question: Do current definitions and practices related to failures of onsite wastewater systems lead to the protection of public health? • Activities: • Conduct a literature review on the definitions of OWW systems’ failure in Rules at state level review and the potential impact of these systems on human health. State Rules from Georgia, North Carolina, and Florida were selected. Assessing the performance of OWW as part of the definition of failure was the main criterion for public health protection. • Contact environmental health officials who are in charge of OWW in county health departments of at least two states. Georgia and North Carolina were conveniently selected because the investigator lived in North Carolina before moving to Georgia in June 2008. • Gather information from county health specialists on the following OWW issues: • a. Procedures to determine failure; • b. Failure rates and data management; • c. Procedures after failure determination; • d. Remediation of systems that failed; • e. Preventative measures to minimize failure; and • f. Limitations on conducting their work. • Assess the status of onsite wastewater systems failure and draft recommendations guided towards enhancing public health protection. GOAL AND OBJECTIVES Goal: To promote a new definition of OWW system failure that includes the system’s performance evaluation to protect water sources and human health. Health Problem: Number of WBDOs associated with drinking water (DW) from private or non-community wells fluctuated between 1999 and 2006, 46% to 30%, without a clear trend. U.S. DW systems may be vulnerable to contamination. Much houses with private wells also have an OWW system. Outcome Objective: December 2009, core group of environmental health practitioners and collaborators be established to design a strategy to achieve new definitions and practices regarding failure of OWW systems. Impact Objective: By 2010, environmental health specialists in different states will have the knowledge and practice to monitor performance of OWW systems. This practice is expected to be systematically expanded to other states. Figures 1 and 2 illustrate the processes for the implementation of the goal and objectives of this project. CONCLUSIONS • It is important to explore and develop collaboration opportunities with local health departments they are first responders to the environmental public health challenges and emergencies. • There is a need for reviewing and enhancing the definition of failure or malfunctioning of OWW systems given the growing number of reports linking these systems with groundwater and surface water contamination. • Most of the environmental health specialists who collaborated with this project have the willingness to keep collaborating, which is encouraging especially if the project is to be continued and expanded to other partners. • It is important that fundamentals of wastewater treatment processes are incorporated into state OWW Rules. BIBLIOGRAPHY Figure 1. Behavior over time • Georgia Department of Human Resources (2007). Rules of Department of Human Resources, Public Health, Chapter 290-5-26, On-Site Sewage Management Systems. • North Carolina Department of Environment and Natural Resources (2006). Title 15A - Department of Environment, Health, and Natural Resources, Chapter 18- Subchapter 18a, Section .1900 - Sewage Treatment and Disposal Systems. • Florida Department of Health (2006). 64e-6: Standards for Onsite Sewage Treatment and Disposal Systems-Rule No. 64E-6.002. Department of Health, Division of Environmental Health. • U.S. Census Bureau (2001). 2001 http://www.census.gov/prod/2002pubs/01statab/construct.pdf and http://www.census.gov/prod/2002pubs/01statab/pop.pdf. Accessed 9/9/2008. • Gelting RJ (2007). Journal of Environmental Health, 69(7):62-63. • Lee SH et al.(2002). Surveillance for waterborne-disease outbreaks – US, 1999-2000. In: MMWR Surveillance Summaries, November 22; 51(SS-8):1-48. • Blackburn BG et al. (2004). Surveillance for waterborne-disease outbreaks associated with drinking water–US, 2001-2002. In: MMWR Surveillance Summaries, October 22; 53(SS-08):23-45. • Liang JL et al. (2006). Surveillance for waterborne-disease outbreaks and outbreaks associated with drinking water and water not intended for drinking–US, 2003-2004. In: MMWR Surveillance Summaries, December 22; 55(SS-12):31-58. • Yoder J et al. (2008). Surveillance for waterborne-disease outbreaks and outbreaks associated with drinking water and water not intended for drinking – US, 2005-2006. In: MMWR Surveillance Summaries, September 12; 57(SS-9):39-69. • Borchardt M.A et al.(2003). Applied and Environmental Microbiology, 69 (2):1172–1180. • Borchardt M.A et al.(2003). Environmental Health Perspectives, 111 (5):742-748. • Ahmed W et al.(2005). Journal of Applied Microbiology, 98:910–920.