The Building Regulations (Northern Ireland) 2012

Cesspools, septic tanks and similar structures

83.—(1) Any cesspool, septic tank or similar structure shall be—

(a) so constructed as to be impervious to both liquid from the inside and subsoil water from the outside; and

(b) so sited—

(i) as not to render liable to pollution any spring, stream, well, adit or other source of water which is used, or is likely to be used, for drinking, domestic or kitchen purposes;

(ii) that there is ready means of access for cleansing it and removing its contents without carrying them through any building in which any person resides or is employed in any manufacture, trade or business, or to which the public has access; and

(iii) as not to be in such proximity to any building in which any person resides or is employed in any manufacture, trade or business, or to which the public has access, as to be liable to become a source of nuisance or a danger to health.

(2) A cesspool shall be—

(a) of suitable depth to enable it to be emptied completely;

(b) properly covered so as to be impervious to surface water and rainwater;

(c) fitted with a suitable manhole cover for the purposes of inspection (including inspection of the inlet), emptying and cleansing;

(d) adequately ventilated;

(e) without any outlet for overflow or discharge other than the outlet provided for emptying or cleansing; and

(f) of a capacity, measured below the level of the inlet, of not less than 18 m³.

(3) Any structure to which paragraph (1) applies other than a cesspool shall be—

(a) of suitable depth;

(b) of adequate size, having in no case a capacity of less than 2.7 m³;

(c) covered or fenced in;

(d) if covered, adequately ventilated and constructed with means of access for the purposes of inspection (including inspection of the inlet and outlet), emptying and cleansing; and

(e) fitted with filter or other treatment facility for effluent (including subsurface irrigation) or both, sited to comply with the requirements of paragraph (1)(b)(i) and (iii).