7


Soil and Sediment


I. BACKGROUND   §7.1

II. SOIL AND SEDIMENT SAMPLING   §7.2

Figure 7-1: Soil and Sediment Sampling Sites III. SOIL AND SEDIMENT ANALYSIS RESULTS   §7.3 Table 7-1: Tritium Results in Soil and Sediment Samples

Table 7-2: Metals and Oil/Grease Results in Soil and Sediment Samples



§7.1      I. BACKGROUND

The analysis of soil and sediment as part of a routine environmental monitoring program can provide information regarding past releases to air or water. DOE guidance recommends¾and Berkeley Lab performs¾annual soil and sediment sampling to determine long-term accumulation trends and baseline profiles.1 No other specific regulatory requirements exist for routinely assessing these media, although any contamination discovered by sampling must be handled according to federal and state hazardous waste regulations.

Details on Berkeley Lab’s soil and sediment program are included in its Environmental Monitoring Plan.2 In 1999, sampling was performed in October before the rainy season. All sampling results are presented in Volume II.

§7.2      II. SOIL AND SEDIMENT SAMPLING

In 1999, soil samples from the top 2 to 5 centimeters (1 to 2 inches) of surface soils were collected from three locations around the site and one off-site environmental monitoring station. See Figure 7-1. Locations were chosen to coincide with ambient-air sampling stations. Samples were analyzed for gross alpha and gross beta radiation, gamma emitters, tritium, metals, moisture content, and pH.

Sediment samples were collected during the same period from main and tributary creek beds of the North Fork of Strawberry Creek and Chicken Creek. See Figure 7-1. Sediment samples were analyzed for gross alpha and gross beta radiation, gamma emitters, tritium, metals, polychlorinated biphenyls (PCBs), petroleum hydrocarbons (diesel fuel and oil and grease), and pH.

Figure 7-1      Soil and Sediment Sampling Sites

§7.3      III. SOIL AND SEDIMENT ANALYSIS RESULTS

All gross alpha, gross beta, and gamma-emitter results were similar to background levels of naturally occurring radioisotopes commonly found in soil and sediment. Tritium levels measured were comparable to results reported for these locations in previous years. In 1999, only three of the eight samples contained detectable levels of tritium. The maximum tritium level in soil was 0.0094 becquerels per gram (Bq/g) (0.25 pCi/g) of soil near Building 69. The maximum tritium level in sediment was 0.0091 Bq/g (0.25 pCi/g) at the North Fork Strawberry Creek-Main location. Table 7-1 summarizes the soil and sediment analysis results for tritium.

Berkeley Lab is currently conducting a corrective action program under the Resource Conservation and Recovery Act of 1976 (RCRA) to investigate soil and groundwater tritium contamination near the National Tritium Labeling Facility. For a summary of the RCRA investigation, see §3.18. For groundwater monitoring results, see §6.11.

Most of the results for metals analyses were within normal levels for soil and sediment, and all were well below regulatory levels.3 Soil concentrations of copper and zinc were slightly higher than normal background levels at Building 50 (244 mg/kg copper) and ENV-B13C (362 mg/kg). These slightly elevated levels may be due to the proximity of galvanized iron (containing zinc) and pressurized wood fencing (containing copper sulfate) at these two locations.


Table 7-1      Tritium Results in Soil and Sediment Samplesa


Sampling location

Matrix

Tritium (Bq/g)b

Building 50

Soil

<0.007c

Building 69

Soil

0.0094

Building 85

Soil

<0.007c

ENV-B13C

Soil

<0.007c

Chicken Creek–Main

Sediment

<0.007c

Chicken Creek–Tributary

Sediment

0.0075

North Fork Strawberry Creek–Main

Sediment

0.0091

North Fork Strawberry Creek–Tributary

Sediment

<0.007c

a One sample per location
b 1 Bq = 27 pCi
c Result below minimum detectable amount

PCB results for sediment samples were below practical quantification limits. Measurements for pH were within the normal range for soils and sediments. The maximum level of oil and grease (2,400 mg/kg) was measured at the Strawberry Creek-Tributary location. Oil and grease contamination is commonly associated with motorized vehicles on roads and parking lots. This location will be sampled in future years to monitor any changes.

Table 7-2 shows sample analysis results for metals (where at least one result was above the limit of quantification) and oil and grease results.