The Public Water Supplies (Scotland) Regulations 2014

PART 8 TREATMENT, RISK ASSESSMENT AND CONTAMINATION FROM PIPES

Treatment of raw water

29.—(1) Subject to paragraph (3), before providing a supply of water for human consumption purposes, Scottish Water must ensure that the water is—

(a) subjected to sufficient preliminary treatment;

(b) disinfected; and

(c) subjected to an adequate treatment process.

(2) Scottish Water must—

(a) design, operate and maintain the disinfection and treatment process so as to keep disinfection and treatment by-products as low as possible without compromising the effectiveness of the disinfection or treatment; and

(b) verify the effectiveness of the disinfection and treatment process.

(3) Where the Scottish Ministers confirm, by notice given to Scottish Water, that they are, in respect of a supply of water specified in the notice (“the specified supply”), satisfied that—

(a) Scottish Water was, or is (for such period as may be specified), unable to comply (in part or otherwise) with paragraph (1) without causing an interruption of the specified supply;

(b) bearing in mind the risks to human health which would be caused by any such interruption, to protect human health, the specified supply should not be interrupted; and

(c) other action (which would not interrupt the specified supply) will be, or has been, taken by Scottish Water to protect human health until it is able to comply with paragraph (1),

Scottish Water may provide the specified supply without complying with paragraph (1).

(4) Where, by virtue of paragraph (3), Scottish Water provides a supply of water for human consumption purposes which does not comply with paragraph (1) it must, notwithstanding paragraph (3), comply with the other requirements of these Regulations (including taking such action as is necessary to ensure that the supply satisfies the requirements of regulation 4(2)).

(5) Scottish Water must, before (or, in so far as it is not reasonably practicable to do so, promptly after) providing a supply of water for human consumption purposes which does not comply with paragraph (1), inform (in so far as it has not already done so) those of its consumers to whom it supplies the water—

(a) that the water has not been subjected to sufficient preliminary treatment, disinfected or, as the case may be, subjected to an adequate treatment process;

(b) of other action that has been taken, or will be taken, to ensure that the supply satisfies the requirements of regulation 4(2); and

(c) of the action (if any) that Scottish Water considers is necessary or desirable for the consumer to take to protect human health.

(6) Paragraph (1) does not require Scottish Water to disinfect such groundwater as the Scottish Ministers may, by notice given to Scottish Water, specify.

(7) For the purposes of this regulation—

(a) “adequate treatment process” means a continuously operated process of blending or purification treatment which removes, reduces or renders harmless any micro-organism, substance or parasite in, or property of, water, so that the water does not constitute a potential danger to human health;

(b) “sufficient preliminary treatment” means the treatment necessary (if any) to—

(i) remove or reduce the value or concentration of any property or substance which would interfere with disinfection; and

(ii) reduce turbidity to less than one Nephelometric Turbidity Unit; and

(c) water is supplied for human consumption purposes when it leaves a treatment works.

Risk assessment of each treatment works and its connected supply system

30.—(1) This regulation applies to each treatment works and its connected supply system from which water is supplied, or is to be supplied, by Scottish Water for human consumption purposes.

(2) Scottish Water must assess each treatment works and its connected supply system (“the combined system”) so as to establish whether or not there is a significant risk of supplying unwholesome water from the combined system (or any part of it).

(3) Each risk assessment must be recorded in writing (or in electronic form) and include—

(a) a description of the methods used to prepare it;

(b) where the assessment establishes that there is no significant risk of supplying unwholesome water from the combined system (or any part of it), a statement confirming this; and

(c) where it establishes that measures have been taken to remove a significant risk of supplying unwholesome water from the combined system (or any part of it)—

(i) monitoring data which verifies this; and

(ii) details of those measures.

(4) Subject to paragraph (5), each risk assessment must be completed (and recorded) before 1st October 2015.

(5) If the combined system (or part of it) is not in use on 1st January 2015, the risk assessment must be completed (and recorded) before the combined system or, as the case may be, that part of it) is used by Scottish Water to supply water for human consumption purposes.

(6) Scottish Water must keep each risk assessment under review.

(7) The Drinking Water Quality Regulator for Scotland may, by notice given to Scottish Water, require it to complete (and record) a risk assessment or, as the case may be, a review by a date specified in the notice.

(8) Where Scottish Water becomes aware of any factors which make it likely that a risk assessment or a review will establish that there is a significant risk of supplying unwholesome water, it must inform the Drinking Water Quality Regulator for Scotland specifying the relevant factors and the measures it is taking or intends to take to mitigate the risk.

Procedure following risk assessment and prohibition of supply

31.—(1) As soon as reasonably practicable after Scottish Water has carried out a risk assessment, or a review of a risk assessment, under regulation 30, it must submit to the Scottish Ministers a copy of the risk assessment or, as the case may be, the review.

(2) Where the assessment or review establishes that there is a significant risk of supplying unwholesome water, Scottish Water must, as soon as reasonably practicable, prepare and submit to the Scottish Ministers a report that—

(a) contains a full explanation including details of every property, organism or substance that has been identified as contributing to the risk; and

(b) specifies the measures to mitigate the risk that Scottish Water—

(i) has made operational as at the date of the report; and

(ii) intends to make operational.

(3) Where the Scottish Ministers have received a report which states that there is or has been a significant risk of supplying unwholesome water, they may, by notice given to Scottish Water, require it—

(a) to maintain such specified measures for such period of time as they consider appropriate to mitigate the risk;

(b) to review, revise or make operational such specified measures by such date as they consider appropriate to mitigate the risk;

(c) to audit whether the measures have been effective by such means as may be specified;

(d) not to supply water for human consumption purposes from specified treatment works or supply systems, or not to so supply water unless specified conditions are satisfied; and

(e) to give the Scottish Ministers such information as they may require to monitor progress towards mitigation of that risk.

(4) In paragraph (3), “specified” means specified in the notice given under that paragraph.

(5) The Scottish Ministers may, by notice given to Scottish Water, revoke or amend a notice given under paragraph (3).

Copper and lead contamination from pipes

32.—(1) Where there is a risk (“the prescribed risk”) that water supplied by Scottish Water would, for the reason mentioned in paragraph (2), after leaving its pipes—

(a) contain a concentration of copper in excess of 2 mg/litre; or

(b) contain a concentration of lead in excess of 10 μg/litre,

Scottish Water must, subject to paragraph (3), treat the water in such a way as it considers will eliminate the prescribed risk or reduce it to a minimum.

(2) The reason referred to in paragraph (1) is the presence in the water of a concentration of copper or lead which is attributable to the fact that copper or lead is the major component of such a pipe as is mentioned in section 76A(3)(a) of the 1980 Act, or its associated fittings.

(3) Paragraph (1) does not require Scottish Water to treat water—

(a) if the treatment is unlikely to achieve a significant reduction in the concentration of copper or lead;

(b) supplied by it to any part of a water supply zone which the Drinking Water Quality Regulator for Scotland for the time being confirms, by notice given to Scottish Water, is in the Regulator’s opinion an insignificant part of that zone; or

(c) if treatment is not reasonably practicable.

(4) Where Scottish Water—

(a) has reason to believe that water supplied by it for human consumption purposes from a pipe to which paragraph (5) applies contains, at the consumer’s tap, a concentration of lead which exceeds 10 µg/l; and

(b) has received from the owner of premises to which water is so supplied notice in writing (or in electronic form)—

(i) of the owner’s intention to replace so much of the pipe as belongs to him; and

(ii) of his desire that Scottish Water replaces the remainder of the pipe,

Scottish Water must modify or replace its part of the pipe.

(5) This paragraph applies to a pipe—

(a) of which the major component is lead;

(b) which is subject to water pressure from a water main or would be so subject but for the closing of some valve; and

(c) which belongs in part to Scottish Water and, as to the remainder, to the owner of the premises to which the pipe supplies water for human consumption purposes.