Guidebook on Water Reuse On-Site Inspection
Project: 04-09
Year Released: 2012
Type: Decision Making Tool
Program: Principal
Funding Partner: Bureau of Reclamation
Total Investment: $177,990 (Cash: $109,990 In-Kind: $68,000)
Principal Investigator: Stephen E. Davis P.E., BCEE, Malcolm Pirnie, the Water Division of ARCADIS
Background
Recommended procedures for on-site inspection and cross connection control that can be adopted by state regulatory and local governmental agencies are needed to manage risks associated with dual water systems involving the provision of reclaimed water. These procedures need to address current techniques, procedures, treatments, and mitigation measures. These procedures would provide an understanding of what can go wrong, why, and what are the possible risks associated with cross connection and backflow events. At the same time, recommended procedures must strike a balance between benefit and cost of compliance.
Developing recommended procedures for cross connection inspection, control, and mitigation procedures would lead to increased public safety and would greatly reduce the stigma associated with the reclaimed water industry. Current utility inspection, control, and mitigation procedures can be highly variable in scope, effort, cost-effectiveness, and diligence.
Goals and Objectives
The project developed a guidebook of industry-wide recommended procedures for use by water and wastewater agencies in planning and implementing on-site inspection and cross connection control programs specifically for reclaimed water systems. The guidance document will inform decisions by purveyors of reclaimed water about on-site inspection practices.
Research Approach
Task 1: Literature Survey. Assemble and summarize information from water and wastewater utilities with existing on-site inspection and cross connection programs. Review appropriate state regulations and guidance/manuals produced by trade associations. Assess common issues and risks involved as well as common mistakes and lessons learned. Assess current techniques, procedures, treatments, and mitigation measures. Summarize the approach that public utilities (besides reclaimed water) take to safeguard customers from the risks posed by supply of electric power, natural gas, and similar commodities.
Task 2: Develop Recommended Procedures Case Study Examples. Generate industry-wide recommended procedures and guiding principles for cross connection inspection, control procedures, mitigation techniques and procedures, and other protocols for reclaimed water systems to follow. Case study examples would be developed to demonstrate the implementation of successful elements of on-site inspection and cross connection control programs. Procedures would include but not be limited to the following areas:
- Residential commercial, agricultural, and industrial cross connection control and backflow prevention;
- Detection and elimination protocols add another level of safeguards for existing and developing systems;
- Research will be required to determine what trace chemicals and test methods should be used to meet the need; and
- Development of case studies by systematically evaluating pre-existing, well-managed programs to aid in developing a best management practices manual for a national standard.
Task 3: Develop Guidebook. Assemble the information gathered in Task 1 and the recommended procedures developed under Task 2 into a guidebook for water and wastewater utilities. A draft, revised draft and final guidebook would be developed for publication by the WateReuse Foundation using the Foundation’s style guide for published reports.
Findings and Conclusions
This report describes example programs used by model water reclamation agencies to help ensure that sites receiving deliveries of nonpotable reclaimed water are free of cross-connections with the potable system and are planned and constructed to minimize the potential for future cross-connections, off-site discharges, and other undesirable situations involving reclaimed water.
This report focuses on three priorities for a successful reclaimed water program:
- To protect the potable water supply from potential contamination by reclaimed water intended for nonpotable use
- To ensure the safe use of reclaimed water to protect on-site personnel, people using the site, and the potable water system
- To build public confidence in the use of reclaimed water for nonpotable purposes through its safe and appropriate use
To achieve these priorities, the report describes a three-step process:
- Preparing the site for reclaimed water service,
- Initial site review, and
- Site inspection.
This report includes reclaimed water site approval procedures of large programs in the four highest-annual-volume reclaimed water use states: California, Arizona, Texas, and Florida. The reclaimed site review, inspection, approval, and periodic review procedures of these utilities provide excellent information for purveyors interested in launching their own new programs.
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