Given the emphasis on the spatial and temporal distribution of water-quality characteristics in Phase II, future efforts could be more hypothesis-driven, seeking to answer specific questions that have yet to be addressed in the MMSD planning area. For example, what are the long-term effects of changing water quality on biotic communities? What is the relative magnitude and contribution of waterborne pathogens from major sources on an annual basis? Phase II results indicated that bioassessment of the streams was a useful tool for assessing overall stream conditions, particularly in combination with the water quality results. Continued biological data collection would enhance understanding of overall water quality and give a long-term picture of stream conditions in the MMSD planning area. Although microbiological data collection during Phase II was, in part, to augment historical data-collection efforts, results suggested the utility of focused studies such as direct testing for pathogenic viruses, as well as studies to determine sources of Cryptosporidium and Giardia within the urban landscape. These microbiological investigations could be designed to (1) define the relative magnitude and contribution of waterborne human pathogenic viruses from major sources on an annual basis, and (2) define the relative loading of Cryptosporidium and Giardia from different land uses and source areas within the urban landscape. Determinations of toxicity levels in the water column, sediment, and SPMDs of urban streams could be integrated into further studies of the relative concentrations and loads of WWCs in the water column, bed sediment, biota, and post-treatment wastewater mixed with lake water. Performed with an integrated approach, these investigations could provide MMSD with a better understanding of the changes and challenges in the MMSD planning area.

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