In Minnesota, pools and spas are required to comply with

the Abigail Taylor Pool Safety Act. 

https://www.revisor.leg.state.mn.us/laws/?key=57146

This act establishes standards for new and existing public pools requiring specific construction and inspections. The bill also expands the licensure requirements to currently unlicensed public pools to include all public pools.

You have 3 basic choices  for your pools and spas under 4 ft. to bring them into compliance by January 1, 2009:

1.  Dual drains with ASME/ANSI approved covers.  You MUST be certain that you have PROPER dual drains, if you are using this option.  (See "Dual Drain" page.)

2 . Gravity drain system with ASME/ANSI approved covers.

3 . An unblockable drain cover that complies with ASME/ANSI Standards.  The Unblockable Drain Cover™ is compliant.

Links

Pool Web Site for MN dept of Health: www.health.state.mn.us/divs/eh/pools/poolincidents.html

MN New Pool Regulations: www.revisor.leg.state.mn.us/bin/bldbill.php?bill=S2833.4.html&session=ls85

State of MN Pool Survey: http://www.health.state.mn.us/divs/eh/pools/forms.html