The actual structure of the mikvah is written in the Talmud and so each mikvah is built using strict rabbinical guidelines.  Park Synagogue's architect consulted with many sources when designing this structure to make sure it would be a "kosher" mikvah--appropriate and useable by all Jews in our community. There are certain requirements needed to make a mikvah halachically correct:

1) That the depth of the mikvah pool is deep enough for an adult to be completely surrounded  by  water, usually shoulder high  

2) That the water in the mikvah has 40 sah of living water, which equates to about 191 gallons.   Forty is symbolic of the 40 weeks of gestation, representing rebirth and renewal.  The living water must be collected through the force of gravity, such as rain.  The rain is permitted to fall into a huge container called the bor which is under the building.  The mikvah pool shares a wall with the bor, and each shared wall has a hole cut in it which can be plugged up or left open to allow more living water to enter the pool.  In order to make the pool legally valid as a mikvah, it is "seeded" with bor water and then filled with regular, chlorinated tap water.  When the hole between the pool and the bor is unplugged so that the waters are touching, the pool becomes a valid mikvah.  There is also a filtration system that filters the water and keeps it clean and warm.