Douglas County Rules and Regulations for Swimming Pools - Cobb ...

to have a minimum of fifty (50’) feet of head.(7) Hydraulic calculations. H ydraulic c alculations s hall be s ubmitted on a pproveddepartment f orms t ogether w ith t he pool pl ans. A ll pool pi pe s izing s hall bedetermined b y a f riction/flow c hart f or s chedule 40 r igid P VC p ipe ba sed on t he“Williams and Hazen” f ormula using a constant of 150 or approved equivalent. Ifapproved, ot her t ypes o f pi ping s hall be s ized i n a ccordance w ith a n a pprovedfriction/flow chart. A copy of the friction/flow chart and a copy of the chart used todetermine equivalent pipe lengths shall be submitted with the plans and specificationsfor new pool construction or for pool piping modification.Part 13 Filtersa.) Design. Filters s hall be s ized to accommodate or ex ceed t he d esign flow r ate o f t hesystem and provide sufficient water clarity as noted in Part10 (c.) (6) Clarity.(1) F ilters s hall m eet t he s tandards of or be l isted i n t he m ost r ecent e dition ofANSI/NSF 50, or other approved certification organization listing.(2) Filters shall be designed so that filtration surfaces can be inspected and serviced.(3) The maximum flow rate of filters shall not exceed the requirements of the mostrecent edition of ANSI/NSF 50 or other approved organization certification listing.b.) Internal pressure. On pr essure-type f ilters, a m eans s hall b e pr ovided t o pe rmit t herelease of internal pressure.(1) Any filter incorporating an automatic internal air release as its principal means ofair release shall have a l id(s) that provide(s) a s low and safe release of pressure as apart of t his de sign a nd s hall ha ve m anual air r eleases i n a ddition t o a utomaticreleases.(2) A s eparation t ank us ed i n c onjunction w ith a f ilter t ank s hall ha ve a m anualmethod of air release or a lid that provides a slow and safe release as it is opened.(3) The following statement shall be conspicuously visible within the area of the airrelease: “ Do not s tart the s ystem a fter ma intenance w ithout f irst ope ning the a irrelease and properly reassembling the filter and separation tank and opening the airrelease valve.”c.) Filter Piping. P iping f urnished with the f ilter shall be of s uitable ma terial c apable ofwithstanding one and one half (1½) times the working pressure. T he suction piping shouldbe of such construction that it will not collapse when there is a complete shut-off of flow onthe suction side of the pump.Cobb and Douglas County Public HealthDouglas Rules and Regs for Swimming Pools23