According to regulations, what is the maximum filtration rate for high rate gravity sand filters?

The maximum filtration rate for high rate gravity sand filters is established at 5.0 gallons per square foot per minute. This rate is crucial for ensuring that these filters operate effectively without risking the quality of the filtered water. Operating at or below this filtration rate helps maintain optimal contact time between the water and the filter media, allowing for better removal of particulates and impurities.

When the rate is exceeded, it can lead to inadequate filtration, increased head loss, and possible breakthrough of particulates, which ultimately compromises the treatment process. Therefore, understanding this limitation is essential for operators to manage surface water treatment systems efficiently and comply with regulations. These guidelines are in place to promote public health and environmental protection through effective water treatment practices.