Reducing non-point DOC and nitrogen exports from rice fields: A pilot study and quantitative survey to determine the effects of different hydrologic management practices : Deliverable 15.3 Final Report

Rice cultivation at any level in the Sacramento–San Joaquin Delta (existing or expanded) compels the need to quantify surface and subsurface loads of dissolved organic carbon (DOC), disinfection byproduct precursors (DBPPs) and nitrogen. This information can be used to develop Best Management Practices (BMPs) to reduce export of these constituents in order to improve drinking water quality. Although rice cultivation in the Delta is relatively limited, several factors outside of this research could contribute to increased rice acreage in the Delta: • Recently developed rice varieties seem more suitable for the Delta climate than earlier varieties which required warmer conditions; • Previous economic analyses (Appendix A.10) suggest rice is more profitable than corn, a dominant land use in the Delta; • Recent studies on wetlands at Twitchell Island suggest rice production can help mitigate oxidative subsidence (Miller et al. 2000); • The different oxidative states that result from flooding in rice as compared to those found in crops that require drained soils may help control crop specific weeds and nematodes when rice is incorporated into a crop rotation; and • Providing flooded conditions during a greater part of the year than other crops may benefit water birds. ... (PDF contains 249 pages)

Water quality monitoring in the Mersey

This is the Water Quality Monitoring in the Mersey Estuary report produced by the Environment Agency in 2001. This report focuses on the Water Quality Monitoring Programme held in the Mersey Estuary. Since the mid-1960s water samples have been collected at approximately monthly intervals along the length of the estuary between Warrington and New Brighton and in later years further off-shore. This data-set provides an invaluable resource to determine how the very large capital spending of recent years has resulted in the dramatic improvements in water quality that we are now able to record. Initially, the interest was focused on parameters such as dissolved oxygen, BOD, nutrients and suspended solids. Over the last decades, as analytical methods have improved, toxic metals and persistent organic compounds have been included in the routine monitoring programme at a limited number of sites. Moreover, with the introduction of the European Water Framework Directive monitoring programmes it was an opportune time to review the Mersey monitoring strategy. This revised monitoring programme required data from several other components (water, sediments, flora, fauna, fish and birds. This report also contains information about Routine monthly surveys, Special surveys, Chloralkali Directive, UKNMP, British Geological Survey, EDMAR and NERC Environmental Diagnostics Thematic Programme.