Filter Wash Process

At any traditional municipality water plant, filtration is the last and most important step in the treatment process. Over time however, debris and particles from the water will be collected in the sand/rock media of the filter. After about 200 hours of operation, these filters must be cleaned to ensure water passes through at the same rate. As particles buildup, water passes through slower. Ensuring that each filter is adequately washed is a typical job task every week. Follow these steps to properly wash a filter.

Always wash a filter with someone nearby. This is just a precaution, as sometimes water may overflow from the filter, causing damage and possible harm. Also, do not lean over the walls of the filter. Falling in would result in bodily injury.

The influent valve is the main source of water coming in. Closing this stops any new water going to be purified from entering the filter.

The effluent valve is at the bottom of the filter where purified water leaves. This completely shuts off any water being treated from leaving.

The drain valve will be kept open throughout the duration of washing, as the filthy water will be drained into the sewers.

Surface wash spinners are similar to the arms in a dish washer machine. These spin throughout the duration of the wash cycle to spray the sand/rock media to cleanse it.

Backwashing is the process of forcing water in a reverse direction. Water is forced upwards to remove the debris that collects over the course of filter operation.

Closing both will stop the cleaning process, allowing the last of the filthy water to be drained.

Once the drain is shut, the water level in the filter we even out. Filter must wait a day before use to allow time for settling of the media.

In this case, 21,185 gallons of water was used to clean the filter. This task generally takes between 15-20 minutes to complete.