A. Setbacks:
1. Heliports. The landing pad perimeter shall be a minimum of:
a. Fifty feet from a property line of the parcel;
b. One thousand two hundred feet from a property line of a noise-sensitive land use;
c. Two thousand four hundred feet from the perimeter of the landing pad of another heliport or helistop; and
d. Three hundred feet from a public right-of-way.
2. Heliport accessory structures. Maintenance and fueling facilities shall be a minimum of fifty feet from a property line of the parcel.
3. Helistops. The landing pad perimeter shall be a minimum of:
a. Fifty feet from a property line of the parcel;
b. One thousand two hundred feet from a property line of a noise-sensitive land use;
c. Two hundred feet from a property line of a noise-sensitive land use for hospital helistops;
d. Three hundred feet from a public right-of-way;
e. A slant range shall be used to measure the above setbacks for rooftop helistops.
B. Permitted hours of operation are between seven a.m. and seven p.m.
C. Noise Testing.
1. If the perimeter of the landing pad is within one mile of a noise-sensitive land use, the applicant shall perform a noise test before submitting the permit application. The test shall be taken:
a. By a member of the Acoustical Society of America, Audio Engineering Society or Institute of Noise Control Engineering;
b. At the property line of the nearest noise-sensitive land use; and
c. Within the hours of operation seven a.m. to seven p.m.
2. Testing shall be performed in accordance with the Helicopter Noise Testing Manual which has been approved by resolution of the board of supervisors.
3. The applicant shall provide written notification to the county zoning inspector two weeks prior to the testing date.
4. The following shall help determine the potential number of operations:
a. Legend:
ANL = Ambient noise level (measured in dBA and averaged over twelve hours);
HNL = Helicopter noise level (measured in dBA as the maximum reading taken during an operation);
dBA = the A-weighted sound pressure level.
b. If the ANL at the property lien of the nearest noise-sensitive land use is less than or equal to fifty-five dBA the following applies:
HNL Decibel Range Less Than or Equal to 55 dBA | Maximum Number of Operations Per Day Limitations set out in Section 18.58.040D. Limits |
Above 55 dBA to 60 dBA | 8 |
Above 60 dBA to 65 dBA | 4 |
Above 65 dBA to 70 dBA | 2 |
Above 70 dBA to 75 dBA | 1 |
Above 75 dBA | 0 |
c. If the ANL exceeds 55 dBA the following applies:
1) If the HNL does not exceed the ANL, then the operation limits in Section 18.58.040D apply;
2) If the HNL exceeds the ANL, then operations shall be limited by the applicable decibel ranges listed above.
D. Number of Operations.
1. Heliports may be subject to limitations on the number of operations as a condition of the use permit. After one year an applicant may request an increase in the numbers of operations by means of the Type III conditional use permit procedure.
2. Helistops shall not exceed ten operations per day.
3. The board of supervisors or the party responsible for approving the permit may establish a lower number of permitted operations due to the proximity and number of noise-sensitive land uses.
E. Approach-departure path shall avoid noise-sensitive land uses and follow major streets when possible.
F. Operations Log. The heliport or helistop permit holder shall log the identification, operation number and arrival-departure time of helicopters using the facility. Upon request the county zoning inspector shall receive a copy of the operation log.
G. Exemptions. Helistops for hospitals are exempt from all but the setback requirements of this section.
(Ord. 1987-61 § 1 (part), 1987)