More than two years ago, reviewers of the Model Plumbing Code began debating how to best update their standards to help municipal officials find the best way to reduce their maintenance costs of sewer lines. One topic of great focus has been determining the best method to capture fats, oils, and grease (collectively referred to as FOG).

In very simple terms, it seems the requirements and specifications of how best to keep FOGs, primarily generated by restaurants and cooking establishments, from entering a sewer system has been traditionally left to be decided by local permitting officials. For example, it's not uncommon for local officials to allow the septic tanks to be used as grease interceptors.

This lack of standardization can lead to confusion. There have also been questions about the efficiency required. Some areas require only a 75% removal rate, while others require higher.

To address these issues, the International Association of Plumbing & Mechanical Officials (IAPMO) formed a FOG task group, which held its last meeting in July. The task group's goal is to coordinate committee efforts of the Uniform Plumbing Code, the International Plumbing Code, and the American Society of Mechanical Engineers. The IAPMO task group's focus was to provide definitive guidelines of the various interceptor systems. There is even an effort to address performance requirements.

Eventually, the task group efforts will become part of IAPMO PS 080-2006 – Grease Interceptors and Clarifiers. Interested producers can monitor the IAPMO standards development process by monitoring postings on the IAPMO Web site at Proposed IAPMO standards and changes are now posted on its Web site for 20 days before publication.

Paralleling the IAPMO efforts, ASTM C-27 on Precast Concrete has formed a task group to develop a standard on precast concrete grease intercepts. The specification describes precast concrete tanks installed to separate fats, oils, grease soap scum, and other typical kitchen wastes associated with the food service industry.

Development of the precast concrete standard began in late 2003. Due to be published later this year, the new ASTM standard (tentatively assigned C 1613) will provide the design and engineering community information on precast concrete grease interceptors.

The scope of the specification will include design requirements, manufacturing practices, and performance requirements for monolithic or sectional precast concrete grease interceptor tanks. Before this effort, there was no standard for precast concrete grease interceptors.

The publication of a precast concrete industry standard comes at an important time. ASTM Committee F-17 on Plastic Piping Systems is releasing its own new ASTM International standard, WK7686 – Specification for High Density Polyethylene Grease Trap Interceptor Units. The committee's proposed standard is intended to provide uniform dimensions, product quality, and adequate structural integrity for plastic grease trap interceptor units.

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IAPMO PS 080-2006 – Grease Interceptors and Clarifiers is the standard that establishes specifications regarding the construction of grease interceptors and clarifiers. Grease interceptors are sized and specified under Appendix H of the Uniform Plumbing Code.