3098                                    LAWS OF MARYLAND                                 Ch. 805

county commissioners shall each respectively determine,
within twenty days after the bonds are presented by the
commission for the signing of such endorsement. In the
event of any liability under the above guarantee, such
liability for each county shall be in such proportion as the
assessable basis of that part of either county within the
sanitary district bears to the assessable basis of the whole
of such district. Notwithstanding the foregoing provisions
of this paragraph, the commission may, at its option and
pursuant to the provisions of section [71-12] 4-3 of this
[Code] ARTICLE, waive the guarantee of such counties above
provided for.

(c)  For the purpose of retiring bonds authorized to be
issued by this section, and payment of the interest thereon,
there shall be levied against all of the assessable property
within the sanitary district, by the county council and by
the county commissioners of Montgomery and Prince George's
counties, annually so long as [said] THE bonds are
outstanding and not paid, a tax sufficient to meet the
interest on [said] THE bonds, and to pay the principal
thereof as the [said] principal and interest mature or
become due; [said] THE tax shall be determined, levied,
collected and paid over to [said] THE commission in the
manner provided by section [6 of said chapter 122, or any
amendment thereof] 4-5 OF THIS ARTICLE, and all of the
provisions of [said] section [6] 4-5 shall apply to the
bonds issued hereunder.

(d)  For the purpose of retiring the bonds authorized
to be issued by this section and the payment of the interest
thereon and for the purpose of paying for the cost of the
maintenance of its sewerage system and its disposal
facilities, including the overhead expense and proper
depreciation allowance, and payments to the commissioners of
the District of Columbia for disposal of sanitary district
sewage, [said] THE commission shall be empowered and
directed to make a sewer usage charge, chargeable against
all properties connected to [said] THE commission's sewerage
system. [Said] THE charges shall be based upon the water
consumption of the properties connected to the sewerage
system, except that where the commission furnishes sewerage
service to a property which is not connected to the
commission's water system the commission shall make a sewer
usage charge on an annual, semi-annual, or monthly basis,
which will fairly and ratably compensate the commission for
the use of the sewerage system by such property, and in
fixing the charge for properties not connected to the water
system the commission shall take into consideration the
usage made of the sewerage system by such property and the
sewer usage charge applicable to like or similar properties
connected to the water system. In the event that water
furnished by the commission to any lot or parcel of land
shall be used exclusively for any purpose which results in
the water not entering the sewerage system of the
commission, then and in that event the owner, tenant or
occupant of such lot or parcel shall not be charged a sewer