24.17.200 Expansions.
(1) The health officer shall require an on-site sewage system and its reserve area be in full compliance with the new system construction standards specified in this regulation for an expansion of a residence or other facility.
(2) Any necessary permits for the on-site sewage system repair or construction must be issued prior to final building plan approval.
(3) For a single-family residence where a detached guest house is proposed (allowed in Clark County in accordance with Section 40.260.010), the following options are possible:
(a) All requirements in Section 24.17.140(2)(d)(i) apply;
(b) The minimum design flow for one additional dwelling is one hundred twenty (120) gallons per bedroom; and
(c) The local health officer may require an increase of the design flow for dwellings with anticipated greater flows.
(4) For a single-family residence that will be converted to a guest house on a lot where a new single-family residence is proposed, the OSS must be sized for the total number of bedrooms for both structures. This is possible through:
(a) Installation of a new OSS to serve both houses and the existing OSS abandoned;
(b) Installation of a new OSS to serve the new house and the existing OSS maintained;
(c) Expansion of the existing or proposed OSS. (Sec. 21 of Ord. 2007-10-01; amended by Sec. 17 of Ord. 2021-11-05; amended by Sec. 16 of Ord. 2025-03-12)