As far as I can tell there are no minimum facilities required for class C pools by the ISPSC. States and/or local health departments often have additional requirements, as well as definitions. As a class C pool, I think the idea is the only people using the pool are occupants of the dwellings that are using it, and therefore have access to their own toilets. Health departments may not agree and in order to avoid "discharge" into the pool, they may require facilities. If you were to use 609, it would probably be over-kill. The ISPSC mandates that A and B pools use the IPC, but makes no mention of class C pools. The IPC sends ALL pools tp 609, which is only for aquatic facilities. I recently asked an ISPSC committee member about this because I too felt it is confusing for the IPC to send everyone to 609. I asked him to address it with the committee but that can take time.
Here is an excerpt from our state division of water quality. It does not exempt their "semi-public pools", which is for use with hotels and mobile home parks, which would probably be closest to what you have. It does exempt "private pools" which include homes, apartments and condo pools. So, while an ISPSC class C pool may not be required to have fixtures by that code, other requirements may exist that the developers need to be aware of.
3.21 TOILETS:
Toilet facilities shall be provided for both males and females and shall be accessible to disabled
persons.
Flush water closets with elongated bowls, and urinals shall be provided and shall be kept clean and
properly maintained. The ratio of water closets shall be one (1) closet and one (1) urinal for each
sixty
(60) men and one (1) water closet for each forty (40) women expected at the time of maximum load.
All fixtures shall be properly protected against back siphonage. Partitions, walls and ceilings
shall be constructed of material not adversely affected by steam, water, or disinfectants.
Toilet rooms shall be ventilated so that no odor nuisance can exist.
3.22 SHOWER FACILITES:
Separate shower facilities shall be provided for males and females shall be accessible to disabled
persons, and, when provided for the exclusive use of swimmers, shall be so located that bathers
must pass through the shower room before entering into the swimming pool area. The minimum number
of showers provided shall be in proportion of one (1) to each forty (40) bathers expected at the
time of maximum load. The ceilings and walls of the shower room or area shall be constructed of
smooth, impervious, easily cleanable material, not adversely affected by steam or water. The floors
of the shower room or area shall be constructed of non-slip, impervious, easily cleanable material,
not adversely affected by steam or water.
Showers shall be supplied with water at a temperature of at least 90°F with a minimum rate of three
(3) gallons of water per shower per minute. Thermostatic tempering, or mixing valves shall be
installed if necessary to prevent scalding of bathers.
Where shower booths are provided in the shower room, the booth partitions shall be of a material
which will not be damaged by shower water and shall have a minimum clearance of six (6) inches
above the floor. Shower rooms shall be provided
light upon all surfaces so that
all parts are visible for easy cleaning.