PLEASE ADDRESS ANY CORRESPONDENCE TO WATER SUPPLY (NETWORK) DEPARTMENT

Your Ref :
Our Ref : WSN 92802/50 Tel : 6330 4108
Date : 1 Dec 2021 E-mail : roland_chan@pub.gov.sg

To Relevant Professional Institutes, Associations Societies, Statutory Boards, Government

Organisations, Developers, Qualified Persons, Professional Engineers, Licensed Plumbers,
Suppliers, Testing Laboratories.

Dear Sir/Madam

SINGAPORE STANDARD SS 636:2018 – CODE OF PRACTICE FOR WATER

SERVICES – AMENDMENT NO. 4

This circular is to inform you of the latest amendments to the Singapore Standard
SS 636:2018 – Code of Practice for Water Services.

2 The amendments (cited as “Amendments No. 4, July 2021”) have been uploaded
by Enterprise Singapore at the Singapore Standards eShop website. You can access the
amendments by scanning the QR code below. A copy of the amendments is also attached.

3 We would like to highlight Section 7.1.19 b) of SS 636:2018, which outlines the

requirement of the installation of an intelligent access / locking system with facial
recognition and remote surveillance capabilities at the access doors and openings to the
rooms / enclosures housing the water tanks to further strengthen its security against
unauthorized access. Please note that the above requirement strictly applies to projects
where the Notification of Water Service Installation (WSI) Works By Professional
Engineer (PUBWTR-0-WSW01) is submitted after 1 April 2022.

4 All Professional Engineers and Licensed Plumbers are reminded to take note of
the amendments to SS 636:2018 and ensure compliance.

5 We would appreciate it if you could bring the contents of this circular to the
attention of your members/staff. Please do not hesitate to contact Mr Zhafri at 6885 2416
or muhd_zhafri_mohd_shaharuddin@pub.gov.sg if you need further clarification.
Yours faithfully

ROLAND CHAN
PRINCIPAL ENGINEER (WATER DEMAND MANAGEMENT & INSPECTORATE)
for DIRECTOR
WATER SUPPLY (NETWORK) DEPARTMENT

Enclosed
 Singapore Standard SS 636 : 2018

Code of practice for water services

AMENDMENT NO. 4
July 2021

1. Page 26, 7.1.13

Replace clause 7.1.13 c) with:

c) properly screened with non-corrodible or corrosion-resistant stainless steel mosquito-

proof netting of aperture size not exceeding 0.65 mm to prevent ingress of any
animal, insect or foreign material. The netting shall be properly secured using a
stainless steel clip.

2. Page 26, 7.1.14

Replace clause 7.1.14 with:

Every isolated compartment of a storage tank shall be fitted with a tap for sampling purposes
located anywhere between the top water level and the outlet pipe level or on the outlet pipe
from the compartment of the storage tanks. If the sampling tap is fitted on the outlet pipe, it
shall be fitted upstream of the valve.  The sampling tap shall be under lock and key and
accessible only to authorised persons.

3. Page 27, 7.1.17

Replace clause 7.1.17 with:

Every wash-out pipe from the bottom of the storage tank shall be fitted with a tap before the
valve for sampling purposes and such a tap shall be under lock and key and accessible only
to authorised persons.

4. Page 27, 7.1.19

Replace clause 7.1.19 b) with:

b) The access door at each tank enclosure (e.g. fencing gate) and its ancillary
equipment including all water tank covers shall be securely locked with high-quality,
strong and durable hinges, latches and locks with non-duplicable keys (i.e. patented
keys that cannot be duplicated without proper authorisation). Alternatively, smart /
intelligent biometric locking systems affording equivalent level of security shall be
provided.

For access doors and openings to the rooms / enclosures housing the water tanks,
an intelligent access / locking system with facial recognition and remote surveillance
capabilities shall be provided, and this can replace the mechanical lock and key
system. Where multiple roof tanks enclosures are provided at the rooftop, the
intelligent access / locking system shall be provided only for access to roof, as a first
line of security. The locking system shall detect and send alerts to a backend
monitoring station in the event of abnormal events such as forced entry, access by
unauthorised personnel and tampering of the system. This locking system shall have
a comprehensive audit trail.

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 Singapore Standard SS 636 : 2018
Amendment No. 4

5. Page 29, 7.3.9

Insert the following new clause 7.3.9 after 7.3.8:

The manufacturer’s or supplier’s specifications and instructions of all water fittings and
materials shall be strictly followed during installation, maintenance, inspection, replacement
and repairs.

6. Page 52, 10.4.11

Replace clause 10.4.11 with:

All vents and pipe ends shall be properly covered with non-corrodible or corrosion-resistant
stainless steel nettings to prevent the ingress of any animal, insect or foreign matter into the
tanks. These nettings shall be properly secured using stainless steel clips that are in
good condition and have not been tampered with.

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Background
Intent: To Enhance Water Tank Security

 Water tank security is critical as it has a direct impact on the

quality of water supply to consumers

 PUB collaborated with HDB to explore technological solutions

such as Facial Recognition System (FRS) to mitigate the risk of
unauthorized access into the restricted areas within HDB blocks
given existing measures

Enhanced Water Tank  Following a successful pilot trial at Punggol Northshore, HDB has
implemented FRS for new HDB BTOs launched from Nov 2020
Security Measures
 SS 636 (Code of Practice for Water Services) amended to make it
Zhafri Shah mandatory for FRS to be installed at all buildings with water tanks
Water Supply Network Department except landed residential properties HDB Pump Room
(housing low level tank)

30 Nov 2021

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Singapore Standard SS 636 - Amendment No. 4 July 2021 Enhanced Security Measures for Water Tanks
Replacement of clause 7.1.19 (b)
A Facial Recognition System (FRS) shall be provided to enhance the security of
potable water tanks. The FRS shall include (but not limited to) the following
7.1.19 For water tanks in developments other than landed
residential premises:
functionalities:-
4. Page 27, 7.1.19
(a) the water tanks and their ancillary equipment shall be Replace clause 7.1.19 (b) with:
housed in an adequately secured and locked dedicated (b) The access door at each tank enclosure (e.g. fencing gate) and its
tank/pump room or located within an adequately secured ancillary equipment including all water tank covers shall be securely Enable secure access control via facial authentication
and locked enclosure. The room/enclosure housing the locked with high-quality, strong and durable hinges, latches and locks
water tanks and their ancillary equipment shall be with non duplicable keys (i.e. patented keys that cannot be
segregated from other services such as equipment for duplicated without proper authorisation). Alternatively, smart /
telecommunications, lifts, firefighting or ACMV. The intelligent biometric locking systems affording equivalent level of
enclosure for water storage tanks shall not be used for security shall be provided. Detect and send real-time alerts to a backend monitoring
storage of items such as flammable liquids or chemicals.
For access doors and openings to the rooms / enclosures housing the
station in the event of abnormal activities such as:
(b) all water tank covers and access doors and openings to the water tanks, an intelligent access / locking system with facial
recognition and remote surveillance capabilities shall be provided,
a. Forced entry
rooms/enclosures housing the water tanks and their ancillary
and this can replace the mechanical lock and key system. Where
equipment shall be securely locked with high-quality, strong
multiple roof tanks enclosures are provided at the rooftop, the
b. Access by unauthorized personnel
and durable hinges, latches and locks with non-duplicable keys
intelligent access / locking system shall be provided only for access to
(i.e. patented keys that cannot be duplicated without proper
authorisation). roof, as a first line of security. The locking system shall detect and c. Tampering of system
send alerts to a backend monitoring station in the event of abnormal
(c) all water tank covers shall be adequately secured by bolting events such as forced entry, access by unauthorised personnel and
or fastening with stainless steel brackets/fasteners that are tampering of the system. This locking system shall have a
integrated with the tanks or otherwise fastened onto the tanks comprehensive audit trail. Provide a comprehensive audit trail
with non-corrodible or corrosion-resistant tapered round nuts.

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Where shall FRS be installed? Which access door? Schematic for Low level tanks

Are there multiple enclosures

Tanks level Where shall FRS be installed? Area/room with single Area/room with multiple
housing the water tanks?
tank enclosure tank enclosures
No FRS shall be installed at the last access
(e.g. HDB Pump Room) door leading to the low level tanks.
Low level Access door (optional) Access door (optional)
tanks Yes FRS shall be installed at each of the last
FRS FRS Other Services
(e.g. 3 x tank clusters at access door leading to the low level tanks FRS Other Services
Condo basement carparks) (i.e. each tank cluster) Fence gate
No
(e.g. rooftop with 1 tank FRS shall be installed at the last access
Fence gate
enclosure typically at small door leading to the high level tanks.
High level private buildings)
tanks FRS can be provided at the common
Yes access door to the roof. Not compulsory
(e.g. most HDB rooftops) to install FRS at each of the last access
Fencing Fencing Fencing
door to the high level tanks.

Fence gate = last access door

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Schematic for High level tanks What if there are no Other Services?

Rooftop with single tank Rooftop with multiple Area/room/rooftop with

FRS
enclosure tank enclosures FRS water tanks only
(strictly no Other Services)
Other services refer to services
Access door Access door other than the potable water
Access door
service installations (WSI). These
FRS Other Services Fence gate with Padlock Other Services
include but not limited to:
Fence gate • Fire services
• Telco service
• Solar panel equipment
• Lift services/motor room
• NEWater/Sanitary services
• Other maintenance services (e.g.
Gondola, ACMV etc)
Fencing Fencing Fencing

Fence gate = last access door

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FAQs FAQs
1. When will the new security requirements (i.e. FRS) be enforced? 5. “Alternatively, smart / intelligent biometric locking systems affording equivalent level of security
The requirements strictly apply to projects where the Notification of Water Service Installation (WSI) shall be provided.” Is biometric only limited to fingerprint access?
Works By Professional Engineer is submitted after 1 April 2022. We will issue a circular in Dec 2021 to If there are multiple water tank enclosures provided at the rooftop, FRS can be provided at the common
notify the industry on the new requirements. access to roof, as a first line of security. In this case, the access door at each tank enclosure can be secured
using conventional mechanical locking system OR other forms of biometric security solutions such as
2. Where shall FRS be installed for Intermediate level tanks? fingerprint, iris or even facial recognition technology.
Same as Low level tanks. FRS shall be installed at the last access door leading to the intermediate level Similarly, biometric locks can also be installed at all water tank covers (i.e. replace conventional padlock).
tanks. If there are multiple enclosures, each of the last access door shall be provided with FRS.
6. Does this mean that no more conventional mechanical locking system is allowed?
3. Why are there different requirements for low level and high level tanks? If there are multiple water tank enclosures provided at the rooftop, FRS can be provided at the common
access to roof, as a first line of security. It is not compulsory to install FRS at each water tank enclosure (i.e.
Low level tanks and intermediate tanks are generally more accessible compared to high level tanks.
conventional mechanical locking system is still allowed at fence gates).
For example, low level tanks are typically located at the basement carpark whereas high level tanks
are housed within the rooftop with limited access (accessible by maintenance personnel only).
7. Are there any specific locations where the FRS cannot be installed? Can the FRS be installed at any
part of the common access to the roof?
4. Who maintains the FRS?
To comply with the Fire Code, the FRS should NOT be installed directly in front or adjacent to the exit door
It is the legal responsibility of the Town Councils, MCSTs and building owners to ensure proper security which leads to the common corridor. Instead, it should be installed at a higher position, as close to the
of the water tanks including the maintenance of the FRS within their premises. rooftop level as possible. If in doubt, please approach SCDF Fire Safety Department (FSD) for clarification.

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FAQs Summary of Water Tank Security Measures

8. Must be FRS record video footage at times even when it is not in use? How long must the footage
be kept?
Security Measures
While recommended, it is not compulsory for the FRS to function as a live CCTV. The FRS should only Components
capture the essential moments with the necessary date/time stamps (e.g. short video clips during point of
Detect & Respond • FRS at access doors housing water tanks (NEW)
access, abnormal events such as brute forced entry, when the access door is open etc.).
(Infrastructural & • Building owners to timely respond and investigate into alerts of abnormal events
Should the FRS double as a live CCTV, the CCTV footage should be kept for a month (i.e. 30 days), which is Operational) triggered by FRS
the standard industry practice.
Notwithstanding, the backend system should keep all access records (in soft copy written format) of Deter & Delay • Locks with non-duplicable keys at access doors & tank covers
persons granted access to the restricted areas housing the water tanks for a minimum period of 1 year. (Infrastructural) • Stainless steel brackets at tank covers
• Dedicated fencing enclosure to segregate water tanks (Notification submitted after
March 2015)

Deter & Delay • Building owners to keep proper access records (e.g. key movement book)
(Operational) • Building owners to conduct regular checks at water tank areas

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 Thank you

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