Current through Register Vol. 51, No. 19, September 20, 2024
A. Gauges and
Release Valves. An owner shall ensure that the circulation system for a
recreational pool, semipublic pool, or public spa includes the following:
(1) A pressure gauge on the filter or on the
influent side of the filter piping;
(2) A pressure gauge on the effluent side of
the filter piping;
(3) A vacuum or
compound gauge on the influent side of a pump;
(4) A flow meter that:
(a) Indicates the rate of flow through the
circulation system;
(b) Has a
permanent scale readable in gallons per minute;
(c) Is accurate to within 10 percent of the
actual flow; and
(d) Reads in the
range encompassing the minimum and maximum flow rate;
(5) A thermometer on the return line to a
pool or spa if the circulation system includes a heating system; and
(6) A manually operated air release valve on
a pressure filter or a separation tank, or both.
B. Turnover Rate. An owner shall ensure that:
(1) A recreational pool, semipublic pool, or
public spa is constructed to produce the following minimum turnover rates, with
continuous 24-hour flow:
(a) Pools for
swimming and diving: Minimum turnover rate = volume of pool in gallons/480
minutes;
(b) Pools for water
recreational attractions and therapy: Minimum turnover rate = volume of pool in
gallons/360 minutes;
(c) Pools for
wading have a minimum turnover rate equal to the greater of:
(i) Volume of pool in gallons/120 minutes;
or
(ii) The minimum flow required
for the skimmer system and main drain to operate according to the
manufacturer's specifications; and
(d) Spas: Minimum turnover rate = volume of
spa/30 minutes;
(2) The
flow through a circulation system is maintained between the minimum turnover
rate and the design capacity of the filter system and associated piping;
and
(3) A limited public-use pool
has a turnover rate in conformance with:
(a)
American National Standard for Residential Inground Swimming Pools;
or
(b) American National Standard
for Aboveground/Onground Residential Swimming Pools.
C. Head Loss Calculations. An
owner of a recreational pool, semipublic pool, or public spa shall ensure that
head loss calculations include the following:
(1) Piping head loss, found by using:
(a) The Hazen-Williams formula which is:
piping head loss per 100 feet of pipe =
0.2083 (100 / C)1.852(Q1.852/ D4.865)
where: D = nominal inside diameter of pipe;
Q = gpm;
C = constant for inside roughness of pipe;
or
(b) Standard engineering
tables;
(2) Equipment
head loss, including filters, valves, heaters, and other circulation equipment,
based on the manufacturers' specifications for the equipment at the design flow
rate, and filter pressure differential with the filter in a clean and in a
dirty condition;
(3) Elevation of
pump suction and discharge in relation to the pool or spa water surface level;
and
(4) Determination of the total
dynamic head of the circulation system for use in pump selection.
D. Surface to Bottom Flow Ratio.
(1) An owner of a recreational pool,
semipublic pool, or public spa shall ensure that:
(a) Piping for surface outlets is designed to
accommodate 80 percent of the flow; and
(b) Piping for bottom outlets is designed to
accommodate 20 percent of the flow.
(2) An owner of a recreational pool or
semipublic pool may have a gutter surface overflow system with a flow design of
50 percent from the surface outlets and 50 percent from the bottom
outlets.
E. Filter
Capacity. An owner of a recreational pool, semipublic pool, or public spa shall
ensure that a filter:
(1) Operates within the
filter design flow rate;
(2) Has a
filtration capacity sufficient to operate in the range between the minimum
turnover rate and the filter design flow rate when the circulation system is at
the:
(a) Lowest level of calculated total
dynamic head when the filter is in a clean condition; and
(b) Highest level of calculated total dynamic
head when the filter pressure differential is at the maximum allowed in
Regulation .43E of this chapter.
F. Interconnections Between Pools. An owner
of a recreational pool, semipublic pool, or public spa shall ensure that a pool
is not interconnected with a:
(1) Spa or
wading pool except during the filling of a spa or wading pool; and
(2) Spray pool.
G. For a public pool or spa with a flow rate
that is at least 10 percent greater than the design capacity of the filter
system or associated piping or at least 10 percent less than the minimum
turnover rate as specified in §B of this regulation, an owner or operator
shall:
(1) Record the information required in
Regulation .46C of this chapter in 1-hour intervals; and
(2) Prior to restoring normal circulation,
vacate the pool or spa of all bathers until:
(a) 15 minutes after restarting the pump;
and
(b) The water quality is
verified as not exceeding the limits set for a major violation under Regulation
.05(7-1) of this chapter.
