In addition to the developments listed in SMC 14.255.050, the following developments shall be exempt from this chapter:
A. Construction of structures, improvements, and additions of less than 2,500 square feet of total site impervious surface area, which do not increase the risk to the critical area from hazardous substances.
B. Development of parks, recreation facilities, or conservation areas that do not increase the risk to the critical area from hazardous substances.