XN000022-1977-09-22 — Page 5

THURSDAY, SEPTEMBER 22, 1977

+FIRST, THERE ARE A NUMBER OF MINOR CATCHMENT AREAS WHICH WERE PREVIOUSLY CONSIDERED UNECONOMICAL TO DEVELOP OWING TO THE HIGH UNIT COST OF WATER FROM THEM, IN COMPARISON WITH THE UNIT COST OF DESALTED WATER PREVAILING PRIOR TO THE INCREASE IN FUEL OIL PRICES.

+THESE HAVE NOW BEEN RE-EXAMINED AND A PROGRAMME DEVISED FOR BRINGING THEM INTO COMMISSION OVER THE NEXT THREE OR FOUR YEARS, SUBJECT TO THE PROVISION OF THE NECESSARY FUNDS,+ HE SAID.

SECONDLY, HE SAID, WITH THE DEVELOPMENT OF THESE MINOR CATCHMENTS THE FUTURE APPEARED TO BE ALIGNED TO THE CONSTRUCTION OF MORE DESALTING PLANTS.

+SUCH PLANTS NEED NOT NECESSARILY BE CONNECTED WITH A DISTILLATION PROCESS AND SOME DEGREE OF SUCCESS HAS BEEN ACHIEVED IN DESALTING SEA WATER IN REVERSE OSMOSIS PILOT PLANTS ELSEWHERE,+ MR. TUCKER SAID.

THE APPLICATIONS OF REVERSE OSMOSIS TO BRACK ISH WATER ON

A LARGE SCALE, HE SAID, WAS WELL ESTABLISHED.

HE EXPLAINED THAT BASICALLY, THE PROCESS REQUIRED THE APPLICATION OF HIGH PRESSURES TO SEAWATER IN A MEMBRANE CAPSULE, WHEREBY A LARGE PROPORTION OF THE FRESH WATER CONTENT OF THE SEA WATER WAS PASSED THROUGH THE MEMBRANE, WHILE THE MAJOR PART OF THE SALT CONTENT WAS REJECTED TO WASTE,

MR. TUCKER POINTED OUT THAT AT THE PRESENT STATE OF TECHNOLOGY. SUCH PLANTS DID NOT COMPETE ECONOMICALLY WITH DISTILLATION PROCESSES ALTHOUGH THE DEVELOPMENT OF MEMBRANES WAS PROGRESSING IN THE UNITED STATES AND ELSEWHERE.

BUT THE MANUFACTURERS WERE CONFIDENT THAT TECHNOLOGY WOULD IMPROVE WITHIN THE FIVE YEARS OR SO, SO AS TO MAKE SUCH A PROCESS MORE ECONOMICALLY ATTRACTIVE THAN DISTILLATION.

+ THE BENEFIT OF THE REVERSE OSMOSIS PROCESS IS THAT IT CONSUMES MUCH LESS ENERGY THAN A DISTILLATION PROCESS AND IS FAR MORE ACCEPTABLE ENVIRONMENTALLY, AS IT DOES NOT PRODUCE THE ATMOSPHERIC AND THERMAL POLLUTION ASSOCIATED WITH DISTILLATION PROCESSES, HE SAID.

NEVERTHELESS, MR. TUCKER ADDED THAT THE HIGH COST OF DESALTING SEA WATER HAD OF NECESSITY DIRECTED OUR INVESTIGATION INTO OTHER AREAS, PRINCIPALLY TOWARDS INCREASING THE EFFICIENCY OF WATER USAGE.

+

HE SAID THAT IN SOME COUNTRIES, FRESH WATER WAS RECLAIMED FROM WASTE WATER FOR INDUSTRIAL AND IRRIGATION PURPOSES AND WITH SUITABLE TREATMENT, SUCH WATER COULD BE BROUGHT TO A STANDARD SUITABLE FOR HUMAN CONSUMPTION.

/IN FACT,