10. Suffolk county sewer districts. If in the county of Suffolk the plat is not entirely situate within a county, town or village sewer district and the county department of environmental control or the county health department shall have directed that disposal of sewage from the plat shall be provided for by a communal sewerage system, consisting of a treatment plant and collection system, then the Suffolk county sewer agency shall determine, specify and direct the means and method by which the aforesaid system shall be best provided by and at the expense of the developer. Among the alternative means and methods the Suffolk county sewer agency may direct, shall be: (a) that the developer, at its own cost and expense, install, build and construct such system according to such plans, specifications, conditions and guarantees as may be required by the Suffolk county sewer agency, and upon satisfactory completion thereof, the developer shall dedicate and donate same, without cost to the Suffolk county sewer agency, or its nominee, and the developer shall also petition to form a county district, but if the Suffolk county sewer agency shall determine that a suitable complete communal sewerage system of adequate size cannot be properly located in the plat or is otherwise not practical, then, (b) the developer shall install, build and construct temporary cesspools or septic tanks together with a sewage collection system according to such plans, specifications, conditions and guarantees as may be required by the Suffolk county sewer agency, and upon satisfactory completion thereof, the developer shall dedicate and donate same, without cost, to the Suffolk county sewer agency or its nominee, and in addition thereto, the agency may also require the payment to the Suffolk county sewer agency of a sum of money in an amount to be determined by the Suffolk county sewer agency, and the developer shall also petition to form a county district, or (c) the developer shall install, build and construct temporary cesspools or septic tanks and, in addition thereto, shall pay to the Suffolk county sewer agency a sum of money in an amount to be determined by the Suffolk county sewer agency and the developer shall also petition to form a county district, or (d) the developer shall provide such other means and methods or combination thereof as the Suffolk county sewer agency may determine, specify and direct. Any sums paid to the Suffolk county sewer agency pursuant to any provisions of this section, shall constitute a trust fund to be used exclusively for a future communal sewerage system which shall be owned and operated by a county sewer district, which district shall include the subject plat within its bounds. Such moneys and accrued interest, if any, when paid to such district, shall be credited over a period of time determined by the district, pro rata, against the sewer assessment of each tax parcel of the subject plat as may exist at the time of the payment of such moneys and accrued interest to such district.
The useable value of any sewage collection system built under paragraph (b), (c) or (d) of this subdivision shall be credited over a period of time determined by the district, pro rata, against the sewer assessment of each tax parcel of the plat as may exist at the time such system is incorporated into a county sewer district which shall include the subject plat within its bounds.