Gustavus Airport

Gustavus Airport Runway, Apron, and Taxiway Pavement Rehab

Project # Z675170000

Project Description

The Gustavus airport project is needed to maintain the airport and addresses Federal Aviation Administration (FAA) safety concerns. One concern is that extensive cracking in aging pavement on runways and other paved areas used by aircraft increases the risk of damage to aircraft as the pavement condition worsens. The other main concern is that aircraft use designated taxiways when moving between aircraft parking areas and the runway. The Gustavus airport does not have designated taxiways for the shorter crosswind runway. To address FAA's concerns at the Gustavus airport, the project will:

Resurface and rehabilitate existing taxiways, aprons, and runways
Add new taxiways F and G
Install lighting for new taxiway F
Expand paved aircraft parking area enough to make up for existing paved areas that will be converted to designated taxiways
Replace existing aircraft tie downs and install new tie downs in new aircraft parking areas
Cut grooves for improved traction on new runway pavement
Pavement striping

Asphalt Sampling

In March 2021 Shannon & Wilson, Inc. took two preliminary PFAS samples of asphalt from the apron previously known to be an Aircraft Rescue and Firefighting training area. Approximately a week later the department received those results which indicated further investigation was warranted. Utilizing department records and the Howell Report provided by community members within Gustavus, a sampling map was created. The following week samplers from the Department of Environmental Conservation collected 33 primary asphalt samples, 31 new locations and two samples near the original locations, with four field duplicates for PFAS and five samples submitted for analysis using the Synthetic Precipitation Leaching Procedure (SPLP) analytical method. All of the other samples were submitted utilizing modified Environmental Protection Agency Method 537. At this time there are no regulatory levels set for PFAS in asphalt. Out of abundance of caution the department is currently comparing asphalt sample results to the most stringent DEC cleanup level for the migration to groundwater pathway. You can download the regulations here under 18 AAC 75.341, table B2. As the department learns more about PFAS as it relates to asphalt, DOT&PF will continue to work closely with Alaska DEC to determine if these levels are the most appropriate levels to compare to.

The SPLP method is a single point leachate test designed to simulate very specific precipitation conditions.

Ongoing Sampling and Testing

DOT&PF ordered five SPLP Leaching Test samples on May 14, 2021, and results are expected the week of June 14, 2021. The five samples are GST-017-AS through GST-021-AS, taken from runway 11-29. The purpose of these tests is to provide additional guidance for project material reuse.

Three concrete hardstand samples were sent to the lab the week of May 24 and will be tested using the Toxicity Characteristic Leaching Procedure (TCLP) to determine the concrete hardstand solid waste disposal method. The hardstands will be covered while in interim storage in an already contaminated area. Results are expected the week of June 28, 2021.

Four samples from Stockpile #1, generated from green zones within the general aviation apron and runway 2-20, were gathered using Incremental Sampling Methodology (ISM) to confirm project stockpiling procedures to date. The samples were sent to the lab the week of May 24, and results are expected the week of June 28, 2021.

DOT&PF will continue to post information publicly at this website and additional information on the PFAS response can be found at the Alaska DEC Contaminated Sites website.