MONITORING THE HANFORD SITE AND SURROUNDING ENVIRONMENT: LONG-TERM TRENDS 
Robert H. Gray, Manager, Office of Hanford Environment, 
Pacific Northwest Laboratory, Richland, Washington, USA. 
ABSTRACT 
Environmental monitoring has been conducted on the U.S. Department of Energy's (DOE) Hanford Site for 
45 years. Current monitoring objectives are to detect and assess potential impacts of facility 
operations on air, surface and ground water, soil, vegetation, foodstuffs, fish and wildlife. Data from 
monitoring efforts are used to calculate the overall radiological dose to humans working onsite or 
residing in nearby communities. 
In 1988, measured Hanford Site perimeter concentrations of airborne radionuclides were below applicable 
DOE and Environmental Protection Agency guidelines. Tritium and nitrate continued to be the most 
widespread constituents in onsite ground water. Chromium, cyanide, fluoride and carbon tetrachloride 
were found in ground water near operating wells. Concentrations of radionuclides and nonradiological 
water quality in the Columbia River were in compliance with applicable standards. Foodstuffs irrigated 
with river water taken downstream of the Site showed low levels of radionuclides that were similar to 
concentrations in foodstuffs from control areas (i.e., foodstuffs not irrigated with Columbia River 
water). Low levels of 90 Sr and 137 Cs in some onsite wildlife samples were typical of those attributable 
to worldwide fallout, as were concentrations of radionuclides in soils and vegetation from onsite and 
offsite locations. The calculated effective dose potentially received by a maximally exposed individual 
(i.e., a hypothetical individual using worst-case assumptions for all routes of exposure) in 1988 
(0.08 mrem/yr) was similar to doses calculated for 1985 through 1987. 
In addition to monitoring radioactivity in fish and wildlife, population numbers of key species are 
determined. Chinook salmon (Oncorhvnchus tshawvtscha) spawning in the Columbia River at Hanford has 
increased in recent years with a concomitant increase in the number of bald eagles (Haliaeetus 
1eucocephalus) that overwinter onsite. The Site also serves as a nesting area and refuge for great 
basin Canada goose (Branta canadensis moffitti) and great blue heron (Ardea herodias), and supports 
stable or growing populations of elk (Cervus elaphus), mule deer (Odocoileus hemionus), coyote (Canis 
1atrans), and a variety of plants and other animals. 
KEY WORDS: Environmental Monitoring, Radionuclides, Chemicals, Fish, Wildlife 
INTRODUCTION 
The U.S. Department of Energy's (DOE) Hanford 
Site occupies a land area of about 1,450 km 2 
(560 mi 2 ) in semi-arid southeastern Washington, 
U.S.A. (Figure 1). The Columbia River flows 
through the Site and forms part of its eastern 
boundary. Flow of the Columbia River is regu 
lated daily according to electric power demands. 
Although the river was once closed to public 
access, public use for recreational and barge 
traffic is again practical. The southwestern 
portion of the Site includes the southern ter 
minus of the Rattlesnake Hills with elevations 
exceeding 1,000 m. Both unconfined and confined 
aquifers lie beneath the Site. 
Nuclear and non-nuclear industrial and research 
activities have been conducted at Hanford since 
1943. The most environmentally significant acti 
vities have involved the production of nuclear 
materials and the chemical processing and waste 
management associated with the major product, 
plutonium. Byproduct wastes have included gamma, 
beta, and alpha-emitting radionuclides and 
various nonradioactive chemicals in gaseous, 
liquid and solid forms. 
There are currently four major DOE operations 
areas on the Hanford Site (Figure 1). The 
100 Areas located along the Columbia River in 
clude the dual-purpose N Reactor that produced 
plutonium for national defense and steam for the 
Hanford Generating Project (HGP), operated by the 
Washington Public Power Supply System (WPPSS), 
and eight, now deactivated single-purpose, plu 
tonium production reactors. The plutonium 
uranium extraction (PUREX) plant (reactor fuel 
reprocessing), plutonium finishing plant 
(Z Plant), and waste-disposal facilities are 
located in the 200 Areas on a plateau (elevation 
229 m) about 11.3 km west of the Columbia River. 
The 300 Area, located just north of Richland, 
Washington contains the uranium fuel manufacturing 
facilities in support of N Reactor, and research 
and development laboratories. The Fast Flux Test 
Facility which has operated intermittently since 
1981 to test new fuels and materials for future 
breeder reactor technology is located in the 
400 Area. Nongovernment facilities within Hanford 
Site boundaries include HGP, the WPPSS nuclear 
plant (WNP) sites, WNP-1, WNP-2 and WNP-4, 
including one commercial reactor (WNP-2) that 
achieved full operational status in the fall of 
1984, and a commercial low-level radioactive-waste 
burial site near the 200 Areas, operated by U.S. 
Ecology. The Advanced Nuclear Fuels Corp. (for 
merly Exxon) fuel fabrication facility is imme 
diately adjacent to, but not located on, Hanford 
Site property. 
Environmental monitoring has been conducted at 
Hanford for over 45 years. The monitoring program 
is designed to assess potential impacts to 
individuals and populations that may be exposed to 
radionuclides, ionizing radiation and hazardous 
chemicals. Environmental monitoring currently 
includes air, surface and ground water, soil, 
vegetation, foodstuffs (fruits, vegetables, milk), 
fish and wildlife. Fish and wildlife are 
monitored for radioactivity and to determine the 
population status of key species. 
RADIOLOGICAL MONITORING 
Air 
Potential airborne transport of stack releases 
containing radionuclides from Hanford facilities 
offers a direct pathway for human exposure. 
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