8.7.5.2.

(1) The effective area of the surface of the filter medium in each filter bed shall be at least 10 m² and not more than 50 m².

(2) The area described in Sentence 8.7.4.2.(1) shall be designed such that the loading rate does not exceed, for soil having a percolation time set out in Column 1 of Table 8.7.4.1.A., the maximum value set out opposite thereto in Column 2 of Table 8.7.4.1.A.

(3) Except as provided in Sentence (5), where the total daily design sanitary sewage flow does not exceed 3 000 L, the effective area shall be such that the loading on the surface of the filter medium does not exceed 75 L/m² per day.

(4) Except as provided in Sentence (5), where the total daily design sanitary sewage flow exceeds 3 000 L,

(a) the effective area shall be such that the loading on the surface of the filter medium does not exceed 50 L/m² per day, and

(b) the leaching bed shall be comprised of more than one filter bed, each of similar size and adjacent to each other.

(5) Where a treatment unit designed to produce effluent not exceeding the maximum concentrations stipulated in Column 2 of Table 8.6.2.2.A.v1 is used in conjunction with a filter bed, the effective area shall be such that the loading on the surface of the filter medium does not exceed 100 L/m² per day.