XN000022-1990-02-09 — Page 17

16

FRIDAY, FEBRUARY 9, 1990

OF

APART FROM CARBON MONOXIDE, AIR CONTAMINANTS SUCH AS OXIDES NITROGEN AND SMOKE CAN BE FOUND IN THE TUNNELS. MOST OF THESE EMISSIONS ARE FROM DIESEL VEHICLES.

AN EPD SPOKESMAN SAID THE SCOPE OF THE SURVEY REVIEWING TUNNEL AIR QUALITY STANDARDS AND CURRENT AIR CONTROL PRACTICES, MONITORING OF THE AIR POLLUTION INSIDE AUDITING OF THE TUNNEL ANALYSERS, AND REPORTING DEFICIENCIES VENTILATION SYSTEMS.

INCLUDED POLLUTION

TUNNELS,

OF THE

CARBON MONOXIDE AND OXIDES OF NITROGEN WERE MEASURED BY THE EPD'S CONTINUOUS ANALYSERS FOR ABOUT TWO WEEKS IN EACH TUNNEL. AIRBORNE PARTICULATE (DUST) SAMPLES WERE ALSO COLLECTED AND THEY WERE SUBSEQUENTLY ANALYSED IN THE LABORATORY FOR AUTOMOBILE RELATED EMISSIONS.

THE SURVEY SHOWED THAT CARBON MONOXIDE LEVELS WERE WITHIN THE CURRENT TUNNEL OPERATION LIMITS. FOR OXIDES OF NITROGEN. NO RECOGNISED WORLD-WIDE STANDARDS EXIST; BUT THE MEASURED LEVELS WERE BETTER THAN THE JAPANESE STANDARD. THIS INDICATED THAT THERE WAS NO CAUSE FOR ALARM.

NEEDED

VENTILATION FANS WERE GENERALLY OPERATED ON AN "AS BASIS, ALTHOUGH THE CROSS HARBOUR TUNNEL EMPLOYED A CONTINUOUS BASE LOAD OPERATION.

GENERALLY OVER

AUDITING SHOWED THAT THE TUNNEL ANALYSERS WERE CALIBRATED (READING HIGH) AND THUS ERRING ON THE SAFE SIDE.

AS THE TUNNELS WERE BUILT AT DIFFERENT TIMES, SOME OF THE MONITORING EQUIPMENT WAS OBSOLETE AND THERE WAS A LACK OF STANDBY UNITS. ALSO, THERE WERE DIFFERENT PRESET ALARM SETTINGS FOR FAN OPERATION.

ON THE BASIS OF HIGH TUNNEL TEMPERATURE, ODOUR NUISANCE AND THE COMPARATIVELY HIGH PARTICULATE CONCENTRATIONS, THE DEPARTMENT BELIEVED THAT THIS JUSTIFIED COMPLAINTS BY TUNNELS

USERS,

ESPECIALLY IN SUMMER.

THE EPD HAD ALREADY MADE A NUMBER OF RECOMMENDATIONS TO THE TRANSPORT DEPARTMENT ON IMPROVING TUNNEL AIR QUALITY, THE SPOKESMAN SAID.

THESE RECOMMENDATIONS INCLUDED STRENGTHENING OF POLLUTION CRITERIA AS WELL AS ENHANCEMENT OF THE AIR POLLUTION MONITORING CONTROL SYSTEMS.

AND

MORE FREQUENT OPERATION OF FANS BASED ON TRAFFIC CONDITION, POLLUTION CONCENTRATION AND OTHER FACTORS HAD ALSO BEEN PROPOSED.

DISCUSSION ON THE CONCRETE MEASURES TO IMPROVE THE AIR WAS IN PROGRESS BETWEEN THE EPD, THE TRANSPORT DEPARTMENT TUNNEL OPERATORS.

QUALITY

THE

AND

0

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