Residual disinfectant concentration means the concentration of disinfectant measured in mg/L in a representative sample of water.
Diatomaceous earth filtration means a process resulting in substantial particulate removal in which a precoat cake of diatomaceous earth filter media is deposited on a support membrane (septum), and while the water is filtered by passing through the cake on the septum, additional filter media known as body feed is continuously added to the feed water to maintain the permeability of the filter cake.
Mine drainage means any drainage, and any water pumped or siphoned, from an active mining area or a post-mining area. The abbreviation “ml/l” means milliliters per liter.
Septic tank means a water tight tank designed to receive sewage and to effect the adequate decomposition of organic matter in sewage by bacterial action;
Riprap means small, broken stones or boulders placed compactly or irregularly on dykes or similar embankments for protection of earth surfaces against wave action or current;
Basement means any area of the building having its floor subgrade (below ground level) on all sides.
Underground storage tank or “UST” means any one or combination of tanks (including underground pipes connected thereto) that is used to contain an accumulation of regulated substances, and the volume of which (including the volume of underground pipes connected thereto) is 10 percent or more beneath the surface of the ground. This term does not include any: