Environmental Testing Services
Newly Installed Fresh Water Inside Service
After repair or maintenance of fresh water inside service, water testing is required. In order to make sure the consumers could enjoy drinking water with good quality even after repair and maintenance, test is required before WSD supplying water to you.
The table below shows that the acceptable limits of the water quality indicators adopted by either WSD Circular Letter No. 9/2017 or WSD Circular Letter No. 10/2017 Scheme.
| Test Parameter | Acceptance Criteria |
| pH | 6.5-9.2 |
| Turbidity (NTU) | ≤3.0 |
| Colour (HU) | ≤5 |
| Conductivity (at 25°C) (µS/cm) | ≤300 |
| Free Residual Chlorine (mg/L) | >0 and ≤1.5 |
| E. coli (cfu/100mL) | 0 |
| Heterotrophic plate count (cfu/mL) | ≤20 |
| Lead (ppb) | ≤10 |
| Cadmium (ppb) | ≤3 |
| Chromium (ppb) | ≤50 |
| Nickel (ppb) | ≤70 |
| Copper (ppb) | ≤2000 |
| Antimony (ppb) | ≤20 |
References:
- Guide to Application for Water Supply (Oct 2019)
- WSD Circular Letter No. 10/2017 – New Commissioning Requirements for Plumbing Works in Occupied Buildings/Village Houses
- WSD Circular Letter No. 9/2017 – New Commissioning Requirements for New Plumbing Works
- WSD Circular Letter No. 1/2015 – Prohibition of Using Leaded Solder at Fresh Water Inside Services and New Parameters for Testing of Water Sample
- WSD Circular Letter No. 2/2012 – Cleansing and Disinfection of Fresh Water Inside Service
