AUSTRALIAN CAPITAL TERRITORY
Regulations    1987    No. 191

Canberra Sewerage and Water Supply Regulations2 (Amendment)
I, JOHN JOSEPH BROWN, the Minister of State for the Arts, Sport, the Environment, Tourism and Territories, hereby make the following Regulation under the Building and Services Ordinance 1924. 
Dated 14 December 1987.
JOHN BROWN
Minister of State for the Arts, Sport, the Environment, Tourism and Territories

After regulation 100 of the Canberra Sewerage and Water Supply Regulations the following regulation is inserted:
Backflow prevention devices
“100A.  (1)  Where there are reasonable grounds for believing that, as a consequence of the performance of work referred to in regulation 100, non-potable liquids, solids or gases may be introduced into the potable water supply of the Territory:
	(a)	the Engineer shall not grant a permit referred to in that regulation in respect of that work unless the Engineer is satisfied that, in the course of the performance of that work, an appropriate backflow prevention device will be installed; and
	(b)	if such a permit is granted, the person to whom the permit is granted shall, in the course of the performance of that work, install such a device.
“(2)  For the purposes of subregulation (1), an appropriate backflow prevention device is:
	(a)	in relation to non-potable liquids, solids or gases containing matter specified in column 3 in an item in the table in this subregulation:
	(i)	a device specified in column 2 in that item; or
	(ii)	a device referred to in paragraph (b); and
	(b)	in any other case—a device approved by the Engineer, being a device that is so designed as to prevent the introduction into the potable water supply in the Territory of the non-potable liquids, solids or gases which it is reasonably believed may be introduced into that water supply.
TABLE
Item	Device	Matter	
1	Air gap device in which the length of the air gap is at least 3 times greater than the diameter of the inlet pipe.	Bacterial contamination	
2	(a)	Air gap device in which the length of the air gap is at least 3 times greater than the diameter of the inlet pipe.	Toxic chemicals	
	(b)	Reduced pressure zone device including in its assembly:		
	(i)	2 independently acting spring-loaded check valves;
(ii)	a vented and drained spring-loaded pressure differential relief valve located between the check valves;
(iii)	provision for testing the installation against malfunction;
(iv)	isolating valves installed upstream of the first check valve and downstream of the second check valve; and
(v)	a line strainer installed downstream of the upstream isolating valve.		
3	Double check device including in its assembly:	Non-toxic chemicals	
	(a)	2 independently acting spring-loaded check valves;
(b)	provision for testing the installation against malfunction;
(c)	isolating valves installed upstream of the first check valve; and
(d)	a line strainer installed downstream of the upstream isolating valve.		

NOTES
1.	Notified in the Commonwealth of Australia Gazette on 11 January 1988.
2.	Regulations notified in the Gazette on 2 November 1933 as amended by Regulations notified in the Gazette on 30 July 1936, 3 June 1937 and 18 August 1938 and by Regulations 1941 No. 1; 1942 Nos. 2, 9 and 11; 1959 No. 16; 1962 No. 8; 1975 No. 14; 1977 No. 8; 1978 No. 14; 1979 No. 26; 1980 No. 11; 1981 No. 18; 1982 Nos. 10, 18, 35 and 44; 1983 No. 15; 1984 No. 27; 1985 No. 9.