Hong Kong Regulations

BUILDING (STANDARDS OF SANITARY FITMENTS, PLUMBING, DRAINAGE WORKS AND LATRINES) REGULATIONS - REGULATION 47A

Drains and sewers in gathering grounds to be watertight

(1) Every drain or sewer provided for the carriage of foul water from any
building which lies within a gathering ground shall be watertight and shall-

   (a)  be laid in pipes of cast iron or other approved material and be of
        such design and construction as to be capable of resisting the
        pressure to which it is likely to be subjected;

   (b)  have any hatch box constructed on the drain or sewer so that the
        hatch box is capable of resisting the pressure to which it is likely
        to be subjected; and

   (c)  have every joint in the drain or sewer made in lead, or other approved
        material so as to render the drain or sewer capable of resisting the
        pressure to which the drain or sewer is likely to be subjected.

(2) Every joint in a drain or sewer referred to in paragraph (1) shall be made
by bolting the flanges together securely with suitable metallic or asbestos
gaskets or shall be of such other approved construction so as to render the
drain or sewer capable of resisting the pressures to which the drain or sewer
is likely to be subjected.

(3) Hatch boxes shall be provided to a drain or sewer referred to in paragraph
(1)-

   (a)  at intervals not exceeding 30 m in the drain or sewer;

   (b)  at changes of gradient, if the Building Authority so requires; and

   (c)  at every change in direction in the drain or sewer: Provided that no
        hatch box is required where the change in direction does not exceed
        10o and is made by means of a purpose-made bend.

(4) Notwithstanding paragraph (3), not more than one manhole shall be
permitted in each drain or sewer.

(5) Every hatch box shall be constructed of cast iron or other approved
material and shall have a hatch or door securely bolted at the top thereof.

(6) In this regulation-

"gathering ground" (集水區) has the same meaning as in the Waterworks 
Ordinance ( Cap 102);

"hatch box" (檢查箱) means a chamber of such a size and form as readily
allows inspection and testing of the drain or sewer on which it is constructed
and the clearance of obstructions from the drain or sewer. (L.N. 361 of 1980)

"gathering ground" (集水區)

"hatch box" (檢查箱)