A. 
Any new or substantially improved structure which:
(1) 
Will be used for the production or storage of any of the following dangerous materials or substances:
(a) 
Acetone;
(b) 
Ammonia;
(c) 
Benzene;
(d) 
Calcium carbide;
(e) 
Carbon disulfide;
(f) 
Celluloid;
(g) 
Chlorine;
(h) 
Hydrochloric acid;
(i) 
Hydrocyanic acid;
(j) 
Magnesium;
(k) 
Nitric acid and oxides of nitrogen;
(l) 
Pesticides (including insecticides, fungicides and rodenticides);
(m) 
Petroleum products (gasoline, fuel oil, etc.);
(n) 
Phosphorus;
(o) 
Potassium;
(p) 
Radioactive substances, insofar as such substances are not otherwise regulated;
(q) 
Sodium;
(r) 
Sulphur and sulphur product;
(2) 
Will be used for any activity requiring the maintenance of a supply of more than 550 gallons, or other comparable volume, of any of the foregoing dangerous materials or substances on the premises; or
(3) 
Will involve the production, storage or use of any amount of radioactive substances;
(4) 
Shall be subject to the provisions of this section, in addition to all other applicable provisions.
B. 
Within the floodway, any structure of the kind described in Subsection A, above, shall be prohibited.
C. 
Within any floodplain area, any new or substantially improved structure of the kind described in Subsection A, above, shall be prohibited within the area measured 50 feet landward from the top-of-bank of any watercourse.
D. 
Where permitted within any floodplain area, any new or substantially improved residential or nonresidential structure of the type described in Subsection A, above, shall be:
(1) 
Elevated (or in the case of a nonresidential structure only designed and constructed) to remain completely dry up to at least 1 1/2 feet above the base flood elevation in accordance with the standards for complete floodproofing published by the U.S. Army Corps of Engineers or with an equivalent watertight standard. For purposes of this provision, "completely dry" means totally dry during flooding and designed and constructed to prevent the passage of water and water vapor.
(2) 
Designed to prevent pollution from the structure or activity during the course of a base flood.