The department, not later than January 1, 1975, shall prepare and shall submit minimum standards for solid waste handling and disposal for the protection of the public health to the board for inclusion in the state policy for solid waste management required to be adopted pursuant to Section 66770 of the Government Code. The department may adopt varying standards for different areas of the state depending on population density, climate, geology, and other factors relevant to solid waste handling and disposal, and may revise the standards when

appropriate.