
COMMISSION AGENDA
Tay Yoshitani, Chief Executive Officer
October 4, 2011
Page 2 of 5
Lagoon 3 lies in the area within a 10,000-foot radius of the runway centerline, which is defined
as the FAA critical zone with respect to airport wildlife hazard management. Over 75% of all
civil bird-aircraft strikes occur within a horizontal distance of 10,000 feet from an airfield. The
U. S. Department of Agriculture’s (USDA’s) Wildlife Services, through an interagency
agreement with the Federal Aviation Administration, compiled 109,085 wildlife strike reports
from 1,659 USA airports and 534 foreign airports from January 1990 to December 2010. The
number of reported wildlife strikes is estimated to represent only about 39% of the wildlife
strikes that have occurred.
Wildlife strikes are an increasing and significant potential hazard at STIA. A total of 51 wildlife
strikes were recorded at STIA in 2009. In 2010, the number of wildlife strikes increased to 69.
The frequency with which hazardous birds were harassed and lethally removed has increased
dramatically since 2002 when Lagoon 3 monitoring for 1 to 2 hours per week began. During
2009, a total of 144 birds were dispersed and 29 lethally removed. By contrast, in 2010 a total of
607 birds were dispersed and 104 lethally removed.
Besides being an air safety hazard, bird strikes can result in significant costs from the damage to
aircraft. The estimated cost of at least one 2010 bird strike at STIA is known to exceed $450,000.
On April 4, 2006, a US Airways Airbus 319 struck a single Green-winged teal (duck) when over
IWS Lagoon 3. After the bird was ingested in to the engine the aircraft made an precautionary
landing at STIA. The cost to the airline was 85 hours out of service in Seattle. When sufficient
repairs could not be made here, the aircraft was shuttled back to the east coast for further
evaluation and repairs. The final costs for damage and downtime were not available to the Port
of Seattle. Damage from a bird-aircraft strike at the Orlando-Sanford Airport in 2010 reportedly
cost $4,570,000.
Different species of waterfowl and other water associated birds (killdeer, gulls, cormorants) will
access ponds differently, some from above and some from the sides. Therefore, preventing
waterfowl access from the both the top and sides is necessary to effectively discourage their
presence in the area. Considerations in the selection of the best measure to use at Lagoon 3
include the anticipated effectiveness, the size of the pond, constructability, ease of maintenance,
and initial and longer-term maintenance costs. The cost of this project increased from $386,000
to $1,631,000 as Airport staff reviewed various deterrent options and configurations to deter
waterfowl and other water-associated birds and determined that installing netting over the top
and around the perimeter of Lagoon 3 is the only way to positively exclude birds from using the
site. Other measures would be ineffective over the long-term as birds adapt to them or would not
prevent birds from accessing Lagoon 3.
PROJECT JUSTIFICATION:
This is a safety improvement project that will reduce waterfowl access to Lagoon 3 near the
STIA runways. Federal Aviation Regulations (FAR) Part 139.337 require airports, including
STIA, to take immediate measures and mitigate wildlife hazards whenever hazardous conditions
exist. Mitigation plans to reduce the attraction of waterfowl to the area will improve air traffic
safety at STIA.