C.3.5 Other analyses of runoff water

determined. The total or unfiltered sample analysis is not explicitly required

unless water quality standards for chemical contaminants are based on the total

concentration of contaminants. Dissolved to total comparisons for each COC

provides a determination of solubility, which may increase or decrease as the

material dries and oxidizes. Chemical analyses of the runoff samples should be

performed according to the guidance in Chapter 9 of the Upland Testing Manual

(UTM) (USEPA/USACE 1998).

C.3.5 Other analyses of runoff water

Other analyses required for runoff sample include the following and are

conducted on the 250-mL samples collected at each simulation run.

Suspended solids. Suspended solids (SS) in runoff are determined by

filtering a 100-mL volume of each runoff water sample, after vigorous shaking

through a preweighed 1.2-um glass fiber filter. The filter is carefully removed

and dried at 95 EC for 24 hr and reweighed to determine suspended solids in

mg L-1 using the following formula:

SS = (mg dry filter + filtered solids) (mg dry filter) * 10

(C-3)

Determination of water pH. A pH electrode is placed directly into the

runoff water sample collected and the pH is read on a pH meter. May be

required to determine if water quality standards for pH are met.

Electrical conductivity (EC). A conductivity cell is inserted directly into

the runoff samples collected and EC is determined on a conductance meter to

determine EC in mmhos cm-1. This is a concern when discharging runoff water

from a saltwater dredged material into freshwater receiving water.

C.3.6 Interpretation of results

The results of the RSLS test are evaluated as described in Chapter 5. A

computer program (RUNQUAL) is provided for this purpose (Schroeder,

Gibson, and Dordeau 1995) and is a module of the Automated Dredging and

Disposal Alternatives Modeling System (ADDAMS). The program can be

downloaded from the WES/ERDC Environmental Laboratory website:

(http://www.wes.army.mil/el/elmodels/index.html)

C.4 Runoff Toxicity Evaluation

Additional testing may be required to assess the impacts of contaminants in the

dredged material runoff on appropriate sensitive organisms to determine if there is

potential for the dredged material to have an effect due to interactive effects of

multiple contaminants or from contaminants with no WQS. The runoff toxicity

test uses lethality as the primary endpoint because the importance of this endpoint

is easily interpreted. These acute tests use organisms representative of the water

Appendix C Test Procedures for Surface Runoff Discharges