and surrounded by 20-cni-high corrugated aluminum lawn edging which was sunk to the frost. The 

 joints were sealed with mbber cement to prevent oil penetration into the adjacent tundra. 



Fresh crude oil contained in sealed 55-gallon drums was shaken before dispensing. The oil 

 was applied with a 10-liter, hand-pressurized garden sprayer with the nozzle removed. The tip of 

 the sprayer was placed below the foliage and directed at about a 45° angle to the soil surface 

 with applications being made on an approximately 5 - 5 cm grid throughout the plot. Very little 

 oil was spilled on the foliage, thus simulating an oil spill flowing along the soil surface. This 

 application technique seemed to give good distribution of oil throughout the plot. 



The following amounts of oil were applied to each site: 



Site 1 



Sites 



The rates of oil application were essentially determined in the field since no prior informa- 

 tion existed as to the quantities of oil that could be handled and spread uniformly on tundra. The 

 rate of 0.7 liter/m' was the least amount of oil that could be spread and still give adequate sur- 

 face coverage. The amount of oil that could be contained safely set the maximum rate at 12 

 liters/m^ Since the oil was spread on a water- saturated soil, most of the oil floated and the 

 highest rate left a depth of standing oil of 2 to 3 cm. The 5 liters/m' rate was selected because 

 it corresponded to the upper limit that can be tolerated by plants on inorganic soils as reported 

 for the temperate regions. Figure 27 is a close-up of one of the site 3 oil plots. 



The presence of hydrocarbons in the soil was analyzed by a fluorometric comparator technique 

 developed by USA CRREL. Although' the technique was stiU unrefined, the results obtained 

 seemed to give reliable indications of the presence of hydrocaibons derived from petroleum. The tech- 

 nique involved extracting a 1-g sample of the soil with hexane, niLxing, and then saturating 

 a filter paper disk of 5.5 mm diameter with the extract. The filter paper was placed under an 

 ultraviolet light in a black box and the intensity of the fluorescence compared with a series of 

 disks prepared to provide a standard curve from 0.01 to SO mg crude oil ml (IS to 19,000 ppm). 

 The same oil applied to the plots was used in preparing the standard curve. 



The microbial activity of the soils containing the oil spills was also investigated. Reports 

 from temperate climates indicate that the consumption of oxygen increases markedly as the oil 

 is metabolized by microorganisms. Therefore, this may be an indication of both the effect of oil 

 spills on soil systems ;uid the rate of oxidation of the oil. The activity of the soil microorganisms 

 was analyzed by manometric methods. Cores (1.9 cm) were removed from the plots, sampled al llie 

 appropriate intervals, broken into small clods, weighed, and placed in respirometer llasks con- 

 laiiiing KOll m the center well. After eqnilibiiuiii on the respirometer, hourly readings of 



* Phils ll:?a .111(1 1131) were li-rtilized Willi 201010 al ,i rale iit 100 Ih acre. Plols 11:!1) and lUb were 

 reserved fur next year's saiiipluii;. 



75 



