SEA-TAC INTERNATIONAL AIRPORT IMPACT MITIGATION STUDY

Initial Assessment and Recommendations
February 1997
Prepared Under a Grant from the State of Washington administered by Washington State's Department of Community, Trade and Economic Development for the:


City of Burien, Washington
City of Des Moines, Washington
City of Federal Way, Washington
City of Normandy Park, Washington
Highline School District
Highline Community Hospital


Prepared by:
Helmuth, Obata + Kassabaum, Inc. - Dallas, Texas
Raytheon Infrastructure Services, Inc. - Denver and Philadelphia

In Association With:
Thomas/Lane & Associates, Inc. - Seattle, Washington
Michael J. McCormick, AICP - Olympia, Washington


Originally converted to HTML without change by RCAA volunteers for http://www.rcaanews.org/rcaa
and subsequently reformatted at www.wenet.net/~hpb.

Section 9
POTENTIAL SOCIO-ECONOMIC IMPACTS AND MITIGATION


9.08 - IMPACTS ON COMMUNITY DEMOGRAPHIC PROFILES

In Washington State Housing Needs and Market Trends: An Overview (Joshi, et. al., 1989) it was stated that (page 44):

"Most low income households are renters. ... Sixty percent of all Washington households with annual incomes below [75% of state median income] were renters ... The average renter is generally younger, more mobile, and has an income half that of the average homeowner."

Table 9.11 compares the income distribution of owner and renter households.

TABLE 9.11
Income Distribution of Household Owners and Renters --
Washington State

Household Income Status Total Owner Renter

Below 50% State median income26.3%17.9%42.4%
50% to 100% State median income28.4%25.1%34.6%
100% to 165% State median income23.5%27.6%15.7%
Over 165% State median income21.8%29.4%7.3%
Total100.0% 100.0 100.0%

Source: Washington State Housing Needs and Market Trends


Among households that own their own home. 43% are below state median income and 18% are below half of the state's median income. Among households that rent their home, 76% are below state median income and 42% are below half the state's median income. Looked at from another perspective, renter households make up 66% of all households in the state but they account for only 175' of households with incomes below the State median.

A regression model developed by the consultant team that relates Washington State Department of Social and Health Services' (DSHS) "count/use rates" by county to per capita personal income levels in 1994 indicates that the relationship between income levels and need for public services is statistically significant and has a negative sign -- meaning that the need for public services goes up as household incomes (and hence, the percent of owners) fall.

"Use rates" are derived by dividing a county's total DSHS clients, for all types of DSHS services, by the county's total population. Counties where a high percentage of seasonal or transient residents receive DSHS services will have overstated use rates. (Washington State Department of Social and Human Services, Office of Research and Data Analysis, April 1996). The regression models adjusted R2 was 0.15785, the T-statistic for the per capita personal income variable was 2.6335, the regression's F-statistic was 6.9361.

Although a detailed analysis of the relationship between different types of public service needs and the growth of aircraft operations at Sea-Tac International Airport is beyond the work scope of the current socio-economic analysis, it appears from preliminary analysis of available data that such a relationship exists; and that it is statistically meaningful.


9.09 - THE THIRD RUNWAY'S IMPACT UPON COMMUNITY FACILITIES
AND SERVICES

The Third Runway and related Airport facilities, will affect the need for community facilities and services by imparting community demographic profiles in the areas immediately surrounding Sea-Tac International Airport. Many of these communities already have a higher need for community services than other communities in King County -- reflecting, in part, past impacts of the Airport. One way to compare community service needs is by using "service use rates" calculated by the Washington State DSHS for ninety-nine largest cities in the state, including 18 cities located (at least in part) in King County.

DSHS provides a variety of services and grants to individuals and families with one or more of the following difficulties:

Child neglect
Dependent elderly status
Alcohol/substance abuse
Developmental disabilities
Other long-lasting physical/mental disabilities
Poverty
Recent refugee status
Juvenile criminal offenses

DSHS also provides the services in the following administrative categories to individuals and families having these difficulties:

Aging & Adult Services Administration (AASA)
Division of Alcohol & Substance Abuse (DASA)
Division of Children & Family Services (DCFS)
Division of Developmental Disabilities (DDD)
Division of Vocational Rehabilitation (DVR)
Economic Services Administration (ESA)
Juvenile Rehabilitation Administration (JRA)
Medical Assistance Administration (MSA)
Mental Health Division (MHD)

Each fiscal year, DSHS calculates for each city for which it reports the number of clients served in each of Its administrative service categories divided by the city's population. It calls these calculations "service use rates" The most recent rates calculated were for 1994 (Washington State Department of Social and Health Services, Office of Research and Data Analysis, May 1996). The total use rate and the programmatic rates for DCFS, DASA, JRA and ESA are presented in Figures 9.02 - 9.06.

In terms of DSHS's rate for its total army of services, Normandy Park and Federal Way were below the average use rate for all DSHS cities in King County. The DSHS use rate for Burien, Des Moines and Tukwila was above the average,

Although Renton was below the county average and Lake Forest Park was above it, the general pattern was for cities in the south county to have rates above the average and cities in the north county to have use rates below the average (Figure 9.02). In part this likely reflects past impacts of the Airport on the quality of life, property values, and the resulting land use's and demographics of south King County communities.

Figure 9.03 shows the use rate for children and family services among King County cities. Federal Way falls below the county average, while Burien, Des Moines, Normandy Park and Tukwila fall above the county's average use rate. Tukwila has the highest DCFS use rate in King County at 3.8 %. (The county average was calculated by weighting each city by its population.) The weighted total use rate average, for example, was 17.64 % while the unweighted average was 16.19 %.)

The city alcohol and substance abuse rates ire shown In Figure 9.04. Federal Way and Des Moines have rates below the King County average, and Burien, Normandy Park and Tukwila have rates above the county average. To some extent, the TASA use rates reflect the location of alcohol and substance abuse rehabilitation facilities -- which probably accounts for Seattle having the highest DASA rate in the county.

The juvenile rehabilitation rate for King County cities is shown in Figure 9.05. Federal Way, Des Moines and Tukwila are all below the county average while Normandy Park and Burien are above it.

The economic security, services use rate for county cities is shown in Figure 9.06. Normandy Park and Federal Way have rates below the county average, and Burien, Des Moines and Tukwila have rates below the county average.

Overall, Normandy Park and Federal Way have the lowest use rates among the five cities covered by the Sea-Tac International Airport Impact Mitigation Study. This may reflect Federal Wales relatively greater distance from the Airport and both Federal Way's and Normandy Park locations to the west of the Airport's flight tracks, Since the Third Runway will locate a flight tract to the west, these communities Will likely have a greater impact from the Third Runway than they did from Sea-Tac International Airport's first or second runways. The highest social service use rates currently are In Tukwila and Des Moines.

The Third Runway and related Airport facilities will impact community services and facilities in numerous ways. Environmental and transportation impacts during construction will include the movement of construction vehicles over the road system contained within the District, and will likely affect the movement along, and possibly safety, of public streets and parking places. After construction, environmental Impacts will mainly be generated by noise from the growth of aircraft operations from the Third Runway and related Airport facilities will allow Sea-Tac International Airport to exceed its ASV of 380,000 operations after the Year 2000. The impacts of noise on the ability of churches, hospitals, nursing homes, community centers and libraries to function normally is analyzed in the environmental impact sections of this Sea-Tac International Airport Impact Mitigation Study.

As discussed previously, the growth of operations at Sea-Tac International Airport after its 380,000 ASV capacity has been reached around the Year 2000, will mean that the value of residential properties surrounding the Airport will not appreciate as fast as they otherwise would have. The market adjustment to such a relative decline in residential property values will be an alteration in land uses away from owner occupied homes toward renter occupied homes. Since renters have a profile that is younger, more mobile and lower income than owners, communities experiencing the impacts of the Third Runway will have to offer expanded social services if they are to maintain the quality of life achieved in the past.


9.10 - COMMUNITY FACILITIES IMPACTED BY THE THIRD RUNWAY'S FLIGHT TRACK

Employing the DSHS use rates discussed earlier as a guide to the types of impacts the Third Runway and related Airport facilities development will have, the most likely impacts will be generated by the changes in the demographic profile of the population living to the west of the current Sea-Tac International Airport flight tracks. The proportion of renter occupied housing units will likely rise after the Year 2000, and will result in a population needing more child care services, community social services, counseling services and employment assistance services than is either true today or would be true if the Airport were not expanded. Existing facilities at local churches, community centers, schools and libraries will most likely be inadequate to r,ppe with these increased needs and will have to be expanded.

Additional facilities required by Sea-Tac International Airport's Third Runway impacts can be calculated by applying current service use rates per 1,000 of the population, for specific services, to the forecast populations for the impacted cities and subtracting the derived service levels from service requirement levels independently forecast based on the cities' expected demographic shifts. This type of analysis should be reviewed for "reasonableness" by working professionals in both the functional service areas and the agencies/organizations now providing the services in the impacted cities,

The most likely communities to suffer major facility impacts from the Third Runway and related Airport facilities development will be Burien, Des Moines, Normandy Park and Federal Way, Tukwila appears to have suffered the community facility and service need impacts from Sea-Tac International Airport's existing approach/departure flight tracks, but it is to the east of Sea-Tac International Airport and will likely not face the same magnitude of impacts from the approach/departure tracks of the proposed Third Runway. The growth of surface traffic on Pacific Highway South (SR 99) however could easily generate a business environment that gives rise to anti-social and criminal behavior and will require an expansion of Tukwila's public safety personnel and facilities.

No analysis of the community facility requirements was contained in the EIS for the Third Runway and related Airport facilities. The resources and time available under this Sea-Tac International Airport Master Impact Mitigation Study were not sufficient to allow such an analysis to be made using quantifiable research techniques. It is recommended that such a research based analysis be conducted.


Effects of the Third Runway's Flight Track

Community services and facilities in the five impacted communities will be affected by the Third Runway and related Airport facilities in different ways. These include demographic factors, economic factors and psychological factors. None of these factors was considered in the Port of Seattle's Master Plan Update EIS, as a result the information available about these factors only allows for informed speculation and analysis -- based on judgments about likely imparts. Additional research should be conducted on each of these factors to determine its statistical significance and magnitude.

Demographic Factors. These factors have already been discussed as an outcome of the land use changes resulting from the growth of operations after the Year 2000 when the Third Runway and related Airport facilities become operational. The increased proportion of rental housing units in the area will produce a resident population that is younger, more mobile and lower income than today's. Given the established correlation between income and the need for community services and facilities, it is likely that future populations in the impacted communities will require higher service levels per capita and more facilities per capita than does the current population.

Economic Factors. The factors adversely impacting the impacted communities will primarily be the reduction in residential property values that will reduce city tax revenues below what they otherwise would have been.

The decline in relative residential property values between 1995 and the Year 2000 due to the Airport is attributed to a growth of enplanements within the Airport's ASV capacity limit. But the relative property value declines that will reduce revenues after the Year 2000 are attributed to construction of the Third Runway and related Airport facilities.

In addition to the revenue losses to the impacted communities, local home owners will face a relative decline in the value of their property. At the same time that the cities would be faced with a need to increase expenditures per thousand persons residing in the cities in order to maintain its quality life, it would face growing voter resistance to raising local tax rates. The resulting financial squeeze will be a major economic impact on the cities, and it will rival in importance the impact on home owners of the relative decline in the value of their properties.

The calculation of quantitatively probable, rather than illustrative, economic impacts on the impacted communities requires a research effort not possible within the resources available under the current Sea-Tac International Airport Impact Mitigation Study. The entire topic of economic impacts of the Third Runway and related Airport facilities on the community facilities and services (a topic which was not addressed at all in the EIS) needs additional research.

Psychological Factors. The factors impacting the cities' needs for community services and facilities as. a result of the Third Runway could come from several sources. The interruption of normal family functioning at home by aircraft noise could increase stress on affected families. Also, parents and children unable to engage in normal outdoor activities such as playing games or sports, enjoying park lands, or having outdoor barbecues may suffer the psychological stress associated with the disruption of normal neighborhood-based activities. Additional psychological impacts may be the consequence of living in neighborhoods where household turnover is high and interpersonal relationships are unstable; or from living in households with only one parent and/or which is under severe economic and financial pressure.

The current study was not able to quantitatively investigate psychological factors, but the association of such factors with the Types of demographic shifts that will be accentuated by construction of the Third Runway and related Airport facilities is highly probable and warrants further research and analysis.


Need for Additional Community Services/Facilities

The noise Impacts on community facilities to the west of Sea-Tac International Airport caused by the increase in approaching/departing aircraft after the Year 2000, and which are attributable to the Third Runway, related Airport facilities, and expansion of the Airport's ASV capacity, may require remodeling, rebuilding, or other structural alterations. The mitigation of these Third Runway impacts relate to the need to attenuate noise at existing facilities. These requirements are analyzed and their mitigation requirements presented in the environmental part of the Sea-Tac International Airport Impact Mitigation Study.

The impact of the Increase in approaching/departing air-craft after the Year 2000 attributable to the Third Runway, related Airport facilities, and expansion of the Airport's ASV capacity on the value of residential properties surrounding the Airport -- and as a result, the cities' needs to increase expenditures for community services and facilities -- is addressed later in this Section where the mitigation of individual property value losses and community property tax reductions are discussed. Any action that mitigates property losses to individual homeowners or reduces the loss of property tax revenues to communities will also increase the city and School District tax base.

The optimum methods of providing community services as a way to mitigate the demographic shifts that will be caused by the increase in approaching/departing aircraft after the Year 2000 attributable to the Third Runway, related Airport facilities, and expansion of the Airport's ASV capacity will require additional analyst First, quantitative research needs to be conducted 6n the affects of the population's shifting demographic profile on the community service needs of affected families. After which, appropriate mitigation policies need to be formulated by community service professionals within each of the impacted cities. Some of these policies will likely include increased community centers, increased child care, expanded levels of police and fire services, and creation of additional community facilities.

Regardless of which or how many of these types mitigation actions will be determined as both needed and appropriate, it is evident that the impacted cities will require additional resources to mitigate the socioeconomic impacts of the Third Runway and related Airport facilities.


Go to Section 9.11