C.3 Rainfall Simulator/Lysimeter System (RSLS) Procedure for Evaluation of Surface Runoff Quality

be used to ensure effective oxidation of sediment. Samples are then transferred

to the 4-L bottles after oxidation is complete and deionized water is added to

bring the total volume of all samples to 1 L. The samples are shaken for 1 hr as

described above, and on-half of the samples are immediately placed in the

Nalgene containers and preserved with nitric acid to pH 2.0. The remaining

halves are then filtered as described for the wet sediment.

Step 3 - Chemical Analyses. The samples should be analyzed as soon as

possible after extraction. Dissolved and, if required, total concentrations of

desired analytes in the samples should be determined. (If water quality standards

for chemical contaminants are in terms of dissolved concentrations, the total

concentration of contaminants in the runoff samples need not be determined).

C.3 Rainfall Simulator/Lysimeter System (RSLS)

Procedure for Evaluation of Surface Runoff

Quality

The Waterways Experiment Station (WES)/U.S. Army Engineer Research

and Develoment Center (ERDC) rainfall simulator lysimeter system (RSLS)

predicts these effects so that restrictions and/or treatments, such as controlling

movement of suspended solids or providing adequate mixing zones, can be

incorporated into the CDF design. The testing protocol for surface runoff

quality using the RSLS has been applied to dredged material from a number of

locations. Contaminants have included heavy metals, PAHs, PCBs, pesticides,

organotins, and dioxins. Although the RSLS is a very effective tool for

predicting surface runoff quality from upland CDFs, the procedure is time-

consuming, requires a large volume of sediment, and can only be conducted at

the WES/ERDC. However, when the SLRP predicts exceedence of water

quality standards (WQS) after consideration of mixing, the RSLS test may be

used to satisfy the requirements for Section 401 water quality certification.

C.3.1 Materials and apparatus

The following equipment and materials are required to conduct the RSLS

procedure.

Apparatus/Equipment.

a. Rainfall simulator/lysimeter system (see description below).

b. Sampling pump with a minimum of 6 L/min pumping rate.

c. Millipore microanalysis vacuum filter apparatus.

d. 0.45-um membrane filters.

e. 0.7-um glass fiber filters without binders, Type GF/F.

Appendix C Test Procedures for Surface Runoff Discharges