After the effective date of this chapter, pumps and pump motors installed or reinstalled directly over the casing of any well shall be provided with a sanitary seal between the pump base and the concrete base or between the well casing and the pump column pipe. Wells on which a submersible pump or a pump offset from the casing is installed or reinstalled shall have a steel plate fitted over the top of the casing with a watertight seal between the plate and the casing and between the casing and any pipes or conduits which enter the well through the steel plate. No pipe or conduit shall enter the casing from the side except access, air vent, and pump discharge pipes as required by this chapter. Holes in the base of the pump which open into the well shall be sealed. (Prior code § 7810)