We have committed to supply drinking water that meets the international standards. The water quality standard that is applied to our water is the European Standard for Drinking Water. The Laboratory & Research Center analyses our water quality against this standard in accordance with internationally recognized methods:
- For physico-chemical Analysis: the "Standard Methods for Examination of Water and Waste Water" published by the American Public Health Association.
- For microbiological Analysis: the "Standard Methods for Microbiological Analysis" adopted by the United States Environmental Protection Agency (USEPA).
Our water is analyzed at different stages of the treatment and distribution process. The Laboratory performs daily analysis and more comprehensive monthly analysis. Each test focuses on a specific set of quality parameters: For more information about parameters, click here.
Close monitoring of the water quality
The Macao Municipal Laboratory and Macao Water's laboratory jointly keep close surveillance on water quality by taking random samples on the treated water at the outlet of the treatment plants and in the distribution network every day and performing independent analysis. The scope of the Routine Analysis includes:
- 2 samples per day (raw water & treated water in the treatment plant) are taken by the staff of the Water Analysis Division for physico-chemical analysis on 17 quality parameters for the daily analysis (see below).
- Accompanied by the staff of the Municipal Laboratory, our staff take 6 to 10 random samples per day from 76 representative sites in the distribution network for the analysis of the daily analysis parameters (see below).
- In addition, a complete water quality analysis covering 63 quality parameters (see below) is performed every month on 4 samples taken respectively at the raw water intake and treated water outlet of Ilha Verde Treatment Plant and Coloane Treatment Plant.
All daily and monthly analysis reports are submitted to the Municipal Laboratory for comparison and are recorded.
To ensure the filtered water meets the Biological standard (disinfection), the post-chlorination process is applied in the inlet of the treated water tanks. After the post-chlorination, the clean water flows into the treated water tanks and allows for around half an hour of retention. This provides sufficient time for the chlorine to destroy the bacteria.
Parameters that are tested
Daily analysis
The Water Analysis Division of the Laboratory performs an average 4,200 analysis per month!
Raw water
Odour, chloride, ammonia.
Treated water (at the outlet of our treatment plants and in the network)
Organoleptic parameters
Turbidity, colour, taste, odour.
Physico-chemical parameters
Temperature, conductivity, total hardness, alkalinity, free carbon dioxide, pH, chloride, iron, dissolved oxygen, COD (KMnO4 Oxydability).
Undesirable substance
Residual chlorine, ammonia and nitrite.
Microorganism parameters
Total Bacteria Count, Total Coliforms and Fecal Coliforms
Monthly analysis
The following parameters are analyzed in the Raw water in the Ilha Verde treatment plant, the Coloane Treatment Plant, the Main Storage Reservoir, the Sek Pai Van Reservoir,as well as in the treated water at the outlets of the treatment plants of Ilha Verde , Coloane and of the Main Storage Reservoir:
Organoleptic parameters
Turbidity, colour, taste, odour.
Physico-chemical parameters
Temperature, conductivity, total hardness, alkalinity, free carbon dioxide, pH, chloride, iron, dissolved oxygen, COD (KMnO4 Oxydability). What is added: SO4, SiO2, Ca, Mg, Na, K, Al, total solids and suspended solids.
Undesirable substance
Residual chlorine, ammonia and nitrite. What is added for the monthly analysis: Nitrate (NO3), Nitrogen Kjeldahl, Total Organic Cabon (TOC), Sulphide, Anionic Surfactants, Phenols, Boron, Manganese, Copper, Zinc, Phosphorus (P2O5) , Fluoride, Cobalt, Barium, Silver, Polycyclic Aromatic Hydrocarbons, Oil & Grease, Trihalomethanes (THMs), Trihalomethane Formation Potential (THMFP) and UV254.
Toxic substances
Arsenium, Beryllium, Cadmium, Cyanide, Total Chromium, Mercury, Nickel, Lead, Antimony, Selenium and Vanadium.
Microorganism parameters
Total Bacteria Count, Total Coliforms and Fecal Coliforms. What is added for the monthly analysis: Fecal Streptococcus and Clostridium Sulfate reduction bacteria.
