Requirements for systems and components for the storage of water

11w above-mentioned criteria can be achieved by elevated service reservoiI, water towers or by low level service reseivoirs with pumping systems. Service reservoirs may be designed as buried, partially buried or above gnnind structures.

The construction of an elevated service reservoir is advisable if suitable high ground is available.

The construction of a water tower may be considered where the necessary grotuid elevation at a suitable point near the supply area is not available for an elevated service reservoir.

A ptuiiping station with a low level service reservoir is a viable option if measures have been taken to ensure continuity of power supply.

Service reservoirs are mainly constructed from reinforced or pre-stressed concrete. They may also be constructed using steel, glass fibre reinforced plastics or other appropriate materials.

5.2 FunctIonal requirements

5.2.1 Functional requiren.ents — 1afrr quality

5.2.1.1 Gt’ni’,yil

Service reservoirs shall be designed, constructed and operated to prevent contamination or other chemical, l)hysical and biological changes that are detrimental to the water quality. (Refer to water quality regulations.)

5.2.12 Malerials

?sLaterials which meet appropriate test requirements and which will not cause the stored water to fail to comply with the reqtiircnients of appropriate EU Directives or EFTA Regulations shall be used in the structure of the water compartments and in the surfaces in contact with the stored water. Concrete and cement iisnlars generally satisfy this requirement but special care shall be taken if additives are used. In order to facilitate subsequent cleaning and to avoid bacterial growth, internal surfiices shall be as smooth and pore-free as possible. This can be achieved by high quality concrete finishes or by the application of snital)le coatings or linungs.

All metallic parts vulnerable to corrosion shall be protected.

5.2.1.3 Water circulation
Stagnant zones shall be minimized. This can be achieved by suitable design of the physical shape of the water compartments and the arrangement of inlet and outlet pipework for the particular storage capacity.
5.2.1.4 Venlilaf km
refltiJa(Jofl facilities are required in the water compartments in order to permit air movement caused by changing water levels. This may be achieved by natural or forced ventilation. If sjweified by the designer measures shall be taken to safeguard arid control the quality of the air entering or leaving the service reservoir.
5.2.1.5 J-y’reulio,, of conlaininalion
Service reservoirs shall he designed to l)r(vnt the ngress of external water or oilier contaitunalils either through the strnc(ure or any opening, entrance or pipework. Pemument exposure of the water to daylight Shall be avoidc(l.
Entrances and ventilation equipment shall also be designed so that the water cannot he contaminated (e.g. by Polluted air, dust, insecLs and other animals). Design may specify that openings shall not be positioned directly above the free water surface. Wherever positioned they shall be arninged in such a way that no extraneous matter is able to enter the compartment and that all external interference is impeded.
5.2.1.6 Thinpernluru çirfs
There shall be no unacceptable alteration to the stored water caused by heat or cold. Thermal insulation measures may need to be taken to avoid adverse ellEeets on the stored water, the structure and the associated equipment. The thennal insulation measures for service reservoirs shall be apl)ropriale for the local climatic COII(litiOIls, (IN? operating requirenlenis Ui(l in order to minimize condensation within the water conipailments.
5.2.1.7 Mainlaining iiviter qualify
Prior to eonumssloiung, the service reservoir 1n(l the associated equipment shall be carefully checked. cleaned and disinfected.
Inspections shall be carried out before initial eonmussaolung, durnig operation and as part of regular maintenance.
Facilities U) allow the sampling of water, witlnnit entry by persotuiel, shall be provided for each compartment. and if specified by the designer for the inlet and outlet pipes.
5.2.2 Functional requirements一Operation
5.2.2.1 Access and security
(See also A.3.) Service reservoir sites shall be provided with access for routine visits and repair work. Facilities shall be provided to permit cleaning of each compartment independently.
Access to the water compartments, control buildings and all functional equipment shall be designed for safety, including that of personnel, and for ease of operation. Openings shall be dimensioned so as to permit entry for materials and equipment for cleaning, maintenance and repair.
Access to the reservoirs shall always be restricted and controlled. Arrangements shall be such that the minimum number of openings are provided into the water compartments. The compartments may be accessed from the control building or. subject to suitable safegUar(LS, from 11w roof.
Due regard shall be paid to the security of servwe reservoirs with respect to acts of terrorism, vandalism ui(l oilier unknvftil adiit Measures shall be taken to deter, detect and delay intruders.
5.2.2.2 Genernl arm uqemen!
Service reservoirs shall normally comprise at least two compartments (see FIgure 2).
Inlet, outlet, overflow and washout pipework, the necessaiy valves, u1(l if specified by the designer, flow meters and level measuring deices. shall be pmided for each water compartment. A bypass pipework arrangement to cOflflect inlet and outlet pipework shall be provided for all reservoirs. l’he type and arrangement of the valves will depend upon the configuration of the waler distribution system. If nevessaly, underfloor and perimeter (Irains shall be provided.
5.2.2.3 Occrlow
The overflow of each compartment shall be of adequate (linwnsIons to perinit the free escape of excess water and shall normally allow for the discharge of the maximum inflow capable of being delivered to the service reservoir. There shall be no isolation valves on the overflow system. In certain cases where overflow pipe capacity cannot be provided for niaxinnim inflow eflwrgeflcy inlet control nwasures shall be 1W0V1C1V1 . The overflow arrangeiuer its shall not permit the conuunination of the stored water. The overflow should not be pernuuiently cotuiected to a sewer except where this is unavoidable, in which case special attention shall be given to checking the capacity of the sewer, and preventing the backflow of fou] water and gases from the sewer.
5.2.2.4 Monilorinq (See a]soA.4.)
Ser.ice reservoirs shall be Iuotutore(l and controlled. All necessary opemtionai data shall be recorded. The designer shall specify if visual inspection facilities are rtllIir(’(l to observe 11w waler in each compartment.BS EN 1508 pdf free download.Requirements for systems and components for the storage of water