BES - Soil Toxicity Testing Results for Durasoil - One Definitive Bioassay with the Earthworm

Nanette Malan Lake, Laboratory Manager; David Block, Laboratory Director
2005-09-09
Block Environmental Services, Inc.

BLOCK ENVIRONMENTAL SERVICES

2451 Estand Way

Pleasant Hill, CA 94523-3911 (925) 682-7200 FAX 686-0399

 

Soil Toxicity Testing Results for Durasoil ™

One Definitive Bioassay With the Earthworm Eiseniafetida August 2005

 

Prepared For: Chad Falkenberg Soilworks, LLC

681 N. Monterey St., StelOl Gilbert, AZ 85233-3818

 

 

 

BES Sample # 22382

 

 

 

Prepared By:

Block Environmental Services, Inc.

2451 Estand Way Pleasant Hill, CA 94523-3911

(925) 682-7200

September 9, 2005

 

 

David Block Laboratory Director

Nanette Malan Lake Laboratory Manager

 

 

  1. 1.   INTRODUCTION

 

The Federal Water Pollution Control Act Amendments of 1972 (PL 92-500), the Clean Water Act (CWA) ofl977 (PL 95-217), and the Water Quality Act of 1987 (PL 100-4) explicitly state that it is the national policy that the discharge of toxic substances in toxic amounts be prohibited. Toxicity to aquatic life is one of the criteria used to gauge the hazardous potential of a discharged product or waste.

 

The Soilworks LLC product Durasoil™ is designed to mitigate dust formation and increase soil stabilization following product application to slopes and roads. The following testing is designed to address the toxicity ofDurasoil™ to terrestrial invertebrates present in the soils where Durasoil™ is typically applied.

 

To address the soil toxicity of Durasoil™, Block Environmental Services (BES) has conducted a 14-day soil bioassay using the red earthworm Eisenia Jetida. The bioassay was performed by exposing E. fetida to soils treated with increasing concentrations of Durasoil™ and a negative control. A pristine synthetic soil conforming to ASTM specifications was used as both the negative control soil and the soil matrix for Durasoi}TM product applications. This report describes the procedures used and the results obtained for the toxicity test initiated on August 17, 2005.

 

BES is an Environmental Laboratory Accreditation Program certified laboratory (#1812).

 

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  1. 2.    MATERIALS AND METHODS

 

 

2.1             SAMPLE COLLECTION AND HANDLING

 

2.1.1      Sample Collection and Handling- The sample was received at the BES Laboratory on July 25, 2005 and kept at ambient room temperature for the duration of the study

 

2.1.2      Soil preparation - The ensure a pristine soil was used for toxicity testing, a synthetic soil was prepared as described in ASTM E 1676 A2. (Standard Guide for Conducting Laboratory Soil Toxicity or Bioaccumulation Tests with the Lumbricid Earthworm Eisenia Fetida). On a dry weight basis the soil consisted of 70% silica sand, 20% silt/clay (Kaolin) and 10% organic matter (peat moss).

 

Prior to product application, the soil was hydrated to a 45% moisture content with de-ionized water. Durasoil™ was then added to soil aliquots at concentrations equivalent to a product application rate of 1 gallon per 20 square feet , 1 gallon per 35 square feet, and I gallon per 50 square feet of soil.

 

 

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2.2             

II

 

TOXICITY TEST PROCEDURES

 

 

2.2.1        Test Procedures - A detailed procedure is outlined in laboratory standard operating procedures (SOPs) maintained at the BES laboratory. The SOPs for the current study are based upon the following reference:

 

  • Standard Guide for Conducting Laboratory Soil Toxicity or Bioaccumulation Tests with the Lumbricid Earthworm Eisenia Fetida (ASTM 1676-97)

 

Test conditions are summarized in Table 2-1.

 

 

2.2.2      Data Analysis - All toxicity testing results were analyzed using the statistical software SigmaStat (SPSS, Inc; Version 2.03). This software determines if there is a statistically significant reduction in the survival response at the p = 0 05 in a manner consistent with ASTM 1676-97. For the current study, earthworm survival rates from the treated sediments were assessed following 14-days of exposure and directly compared with the organism survival rates observed from the reference control sediment.

 

 

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Table 2-1        Summary Of Testing Parameters by Organism                                        II

 

Test Conditions

E.fetida

Test Type

Whole-sediment toxicity test

Temperature

20 ± 1 °C

Light Intensity

About400-1080lux

Photoperiod

16L:8D

Test Chamber

1 L beaker

Sediment Volume

600 ml

Organism Age

adult

Organism Source

Carolina Biological Supply Company, SC

Organisms/Chamber

10

Replicates/treatment

4

Food Source

None

Feeding

None

Test Duration

14 days

Effects Measured

Survival

Test Acceptability

2: 80% control survival

 

 

 

 

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II

  1. 3.    RESULTS

3.1.1    Sampe andT estm2 summarv

Client Sample Identification

BES Sample#

Sample Dates

Sample Times

Durosoil™

22382

NA

NA

NA - Not available

 

 

3.1.2    Sample Test Duration Summary

 

Test

Time

E. fetida

Date

Time

Initiation

08/17/2005

1000

Termination

08/31/2005

1200

 

3.2              E.jetida END POINT VALUES -

 

Raw Data Summary

Sample Concentration

10 Day Percent Survival

Avera e (%)

Reference Soil

95

lgal/50sq ft

93

1gal/35sq ft

98

lgal/20sq ft

98

 

3.2. l Testing Notes

 

There was no statistically significant reduction for the survival response for any of the test concentrations when compared to the negative Reference control.

 

 

 

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  1. 4.    CONCLUSIONS

 

 

The objective of the current study was to determine if the Durasoil™ treated soils posed a significant risk of toxicity to terrestrial soil-dwelling invertebrates. The results for the soil bioassays using the product Durasoil performed in August 2005 indicate that:

 

  • E. fetida survival was not adversely affected in soils treated with Durasoil™ applications rates of 1 gal/20ft2 or less when compared to the organism response in the Reference control soil.

 

 

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