Overview
Over the past four years, research has been undertaken in Manitoba by the provincial Department of Conservation and the University of Manitoba to examine the potential for impacts on groundwater quality from seepage beneath earthen manure storages and seasonal cattle pens. In this report we present some of the results of these studies and discuss the potential for groundwater quality impacts from these facilities. While the paper has been divided into two separate discussions, the theme of each part is very similar an examination of the rates and concentrations of downward seepage of contaminants beneath areas where manure is concentrated for lengthy periods of time. Both parts of this report also focus on contaminant movement in areas underlain by clays and glacial tills, materials with relatively low permeability that are generally considered to provide good protection for underlying aquifers.

Introduction
There has been a dramatic increase in hog production in North America in recent years. In the last five years the industry has experienced 100% growth in Manitoba, and this trend of rapid expansion is expected to continue. In 1997, over three million hogs were raised in the Province, and sold for an estimated $1.25 billion (Manitoba Pork Council, 2001). Earthen manure storage structures are commonly used in Manitoba to hold liquid hog manure. The primary advantages of earthen storages are their low cost relative to above-ground facilities and the flexibility to design and construct earthen storages to match the needs of the livestock operation. A potential disadvantage is that earthen storages will leak unless they are lined with an impermeable membrane. If a storage is underlain by an aquifer, leakage may result in contamination of groundwater. In 1998, the Livestock Manure and Mortalities Management Regulation (Manitoba Regulation 42/98) was proclaimed as part of Manitobaa