March 2017 - Parks & Recreation - 58

Operations
Multipurpose Pools
By Dennis Berkshire, AFO-I

he days of the old rectilinear neighborhood pool have given way to the modern aquatic center. This is due in part to the need to generate revenue to
offset operating expenses and to meet the public's demand for specialized
programs and services. As we look to the built environment to support these
programs, we have seen the evolution of the multipurpose swimming pool, designed
and built to provide the special needs for a variety of programs and uses, including:
Swimming Area

Recreation Areas

Specialized Use Areas

Lap/Competition lanes,
Diving wells

Water slides, Climbing walls

Lazy rivers, Lilly pad zones

Wading pools

Water basketball

Zip line zones

To meet the specific needs of each
program, a pool requires different water
depths, water temperatures and pool profiles. In some cases, we may choose to have
multiple separate pools to meet the demand of these different aquatic activities.
However, because of the code-required
pool decks surrounding each pool and the
need for spectator areas and paths of travel,
multiple separate pools require more area
than a single multipurpose pool. The cost
savings from developing a smaller, multiuse pool area is especially magnified in a
natatorium where the cost per square foot
is much higher. Multiple pools also require
a larger mechanical space to house the
code-required independent filter and mechanical systems for each pool. The cost
savings from these two combined often
make a multipurpose pool the best choice
for a new or renovated aquatic center.
It is important to keep in mind that
multipurpose pools can create conditions
that require special attention as the varied
programs can put extra loads on the pools,
systems, staff and patrons. Areas that often
require special attention include:
Water Quality

Spectator & Seating Areas

Air Quality

Wayfaring (i.e., traveling on foot)

Paths of Travel Staffing

Parks & Recreation

Most state health codes require a
public swimming pool to have a 65hour turnover rate; wading pools have
a one-hour turnover requirement. So,
how do you manage a pool that has
both areas in a single multipurpose
pool? Most state codes do not give direction on how to handle this. One approach is to calculate the pool volume
in the various pool areas and then add
the flow rates of each area to find a total flow rate for a multipurpose pool.
The chemical feed and control system
also must be upsized to accommodate
these heavy organic loads. Automated
feed systems and controllers are recommended for pools with high organic
loads, to control chloramines and other
undesirable byproducts. Also, supplemental disinfectants, such as an ultraviolet, disinfection system, can help provide
better water quality.
For indoor air quality, the ASHRAE
standards call for four to six air changes per hour for a natatorium. A multipurpose pool, however, will require a
minimum of six to eight air changes
per hour to maintain high, indoor air
quality. Indoor multipurpose pools may
have a greater propensity for chloramine formation, which can require the

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air handling system to have a higher
than normal air change rate. Furthermore, the air handling system needs to
have a purge setting to exhaust the entire volume of natatorium air to clear
chloramines or other air pollutants. The
greater loads of air pollutants close to
the deck make it important to have the
suction taken from this area. As an added layer of air quality, high-volume fans
can be installed in the ceiling above the
pool surface.
ADA-compliant access to a multipurpose pool can be a little tricky. ADA
regulations require every pool to have
a means of ADA-compliant access,
and pools with 300 perimeter feet or
larger are required to have two means
of ADA access. Think about the different zones of the pool and how patrons
needing ADA-complaint devices can
access these zones. To help patrons and
limit staff required to operate the facility, good signage and foot traffic paths
should be provided. Multipurpose pools
with waterpark-type features, such as
slides and current channels, should also
use a safety consultant to help with establishing the quantity and location of
guards. This staffing plan should be addressed during the design of the pool as
it will affect the staffing costs.
In conclusion, a multipurpose pool
can be configured to meet the specialized needs of your entire community.
The pool usage and loads can be much
greater than a rectangular pool, but with
proper planning, maintenance and operation, it can be a community asset for
generations to come.
Dennis Berkshire, AFO-I, is President of the
Aquatic Design Group (dberkshire@
aquaticdesigngroup.com).

March 2017 - Parks & Recreation

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