SAMPLING RIVERINE SEDIMENTS IMPACTED BY ACID-MINE DRAINAGE - PROBLEMSAND SOLUTIONS

Sampling acid mine drainage (AMD) or natural acid rock drainage (ARD)- impacted sediments is complex, requiring appropriate field sampling te chniques to ensure representative samples that are both repeatable and reproducible. The important factors affecting sampling of riverine se diments are examined. These include sample site location, field observ ations, representative sampling, sample collection techniques, and sam ple preservation. A recommended sampling and processing protocol is pr esented for AMD- and ARD-impacted riverine sediments, which includes s ediment sampling, Fe hydroxide flee sampling, chemical analysis, inter stitial (pore) water collection, sediment elutriates, sediment fractio nation, and physical analysis. The importance of bioassay testing is d iscussed, as is quality assurance and assessment approaches to define sediment quality criteria.