18A.60.030 Pierce County Airport – Thun Field Airport Area of Influence.
A. Pierce County Airport-Thun Field Area of Influence. Thun Field Aircraft Accident Safety Zones 1-6.
1. All non-residential uses within Thun Field Area of Influence, Aircraft Accident Safety Zones 1-6, shall be subject to PCC 18A.60.050, Performance Criteria, and PCC 18A.60.030.A.3 through 7. below.
2. No new residential dwelling units shall be permitted in the Thun Field Area of Influence, with the exception of Zones 4 and 6, unless building permits were submitted prior to June 16, 2003. On lots in the Thun Field Area of Influence, with the exception of Zones 4 and 6, containing residential dwellings as of June 16, 2003, no additional dwelling units, including accessory dwelling units, shall be permitted. Remodeling and expansion of existing dwelling units or common areas is permitted as long as the number of dwelling units is not increased over that existing on June 16, 2003.
3. Large concentrations of people shall be prohibited within the Pierce County Airport Area of Influence Aircraft Accident Safety Zones 1-6. Non-residential uses or activities shall meet this standard by complying with either (1) or (2) below:
a. Large concentrations of people shall be calculated by the number of people the proposed building(s) would accommodate per gross acre. The concentration standard varies by Accident Safety Zones (see (b) below).
(1) Calculation Method. To determine the number of people that a building or use would accommodate, the following methods shall be used depending on the type of use:
(a) Other Than Education Use Type. The number of people that a building(s), other than those associated with an Education Use Type, can accommodate shall be calculated by multiplying the total number of proposed parking stalls by two.
|
Example: |
|
|---|---|
|
500 |
(proposed parking stalls) |
|
x 2 |
|
|
1,000 |
(assumed number of people for the site) |
(b) Education Use Type. The number of people that a site associated with an Education Use Type can accommodate shall be the building's maximum occupancy load per the County's adopted Building Code divided by two.
|
Example: |
|
|---|---|
|
1,600 |
(calculated building codes, Title 17C PCC), maximum occupancy load) |
|
÷ 2 |
(reduction figure) |
|
800 |
(assumed number of people for the site) |
(c) Combination of Education and Religious Assembly Use Types on One Site/Building. The number of people that a site can accommodate if it has buildings that facilitate both Education Use Types and Religious Assembly Use Types shall be the total number of proposed parking stalls multiplied by two, or the maximum occupancy load per the County's adopted Building Code for the identified Education Use Type building divided by two, whichever is greater.
|
Examples: |
|
|---|---|
|
Educational Use Type Building |
|
|
900 |
(calculated building codes, Title 17C PCC) maximum occupancy load) |
|
÷ 2 |
(reduction figure) |
|
450 |
(assumed number of people for the site) |
|
|
|
|
Religious Assembly Use Type Building |
|
|
75 |
(proposed parking stalls) |
|
x 2 |
|
|
150 |
(assumed number of people for the site) |
|
In this example, 450 would be the assumed number of people for the site, and used in determining if the use met the standard below. |
|
(2) Standard. The concentration standard for each Safety Accident Zone is defined as follows:
Safety Accident Zone 1, 2, 5 – greater than 5 people per gross acre
Safety Accident Zone 3 – greater than 25 people per gross acre
Safety Accident Zone 4 – greater than 40 people per gross acre
Safety Accident Zone 6 – greater than 100 people per gross acre
|
Example: Zone 6 |
|
|---|---|
|
1,000 |
(assumed number of people for the site per PCC 18A.60.030 A.3.a.(1) |
|
÷ 8 |
(site acreage) |
|
125 |
(concentration of persons per gross acre) |
|
Since 125 persons per gross acres is higher than the standard for Zone 6, 100, the proposed use in this example would not meet the standard and is not allowed; or |
|
b. Alternatively, the prohibition of large concentrations of people within the Pierce County Airport Area of Influence can be accomplished by limiting the building coverage portion of the site. The building coverage associated with a non-residential activity within the Pierce County Airport Area of Influence cannot exceed 20 percent of the site in Safety Accident Zones 1-5, and 25 percent in Safety Accident Zone 6.
4. Any buildings and structures that would penetrate the imaginary airspace surfaces for the Pierce County Airport (Thun Field) as defined in Title 14 CFR (Code of Federal Regulations) FAR (Federal Aviation Regulations) Part 77 "Objects affecting navigable airspace" shall be prohibited. The imaginary airspace surfaces (maximum elevations) are identified on the Pierce County Airport – Thun Field Airport Airspace Drawing.
5. No use, building or structure that promotes large concentrations of bulk storage of flammable/hazardous substances or materials shall be permitted within Accident Safety Zones 1-5.
6. Prior to issuance of a Building Permit for new construction within the Pierce County Airport Area of Influence, the property owner must sign an airport proximity disclosure statement and record it in the Pierce County Auditor's office. The disclosure statement acknowledges that the property is located within 4,500 feet of the Pierce County Airport as indicated on the Pierce County Airport Area of Influence map and that the property may be impacted by low flying aircraft, noise, vibration, odors, and other associated aviation activities.
7. The expansion of an existing business within the Pierce County Airport Area of Influence shall comply with PCC 18A.60.050, Performance Criteria, and 18A.60.030 A.4. and 5.