1. a) Before a community water supply may use deep bed rapid rate filters, a pilot study must be completed and approved by the Agency.
2. b) The final filter design must be based on the pilot plant studies and must comply with all applicable portions of Section 604.605.

Deep bed rapid rate gravity filters refers to rapid rate gravity filters with filter material depths equal to or greater than 48 inches. Filter media sizes are typically larger than those listed in Section 604.605(f)(4).