If the drinking water supply is contaminated, the choices are to use an alternate water supply or treat the water.
(the drinking water supply; is contaminated; ) (the choices; are; to use an alternate water supply or treat the water) (the choices; to use; an alternate water supply) (the choices; to treat; the water)
the drinking water supply the choices the choices the choices
is contaminated are to use to treat
to use an alternate water supply or treat the water
an alternate water supply
the water