The Environmental Protection Agency estimates that more than 40% of our assessed waters still do not meet the water quality standards that states, territories, and authorized tribes have set for them. These waters include approximately 300,000 miles of rivers and shorelines. It includes approximately 5 million acres of lakes polluted mostly by sediments, excess nutrients, and harmful microorganisms. At least 218 million people live within 10 miles of these impaired waters. TMDL (Total Maximum Daily Load) is defined by the EPA as, a calculation of the maximum amount of a pollutant that a body of water can receive and still meet water quality standards, and an allocation of that amount to the pollutants sources. TMDLs in the Urban Environment contains a variety of urban TMDL case studies that have been accepted by the appropriate state regulatory bodies. These TMDLs are examples of acceptable modeling, acceptable pollutant allocations, and in some cases, acceptable implementation plans. ASCE s Task Committee for Urban TMDLs presents this book to inform stakeholders of the expectations of permitting agencies, and to compel the best management practices and policy actions to meet these TMDLs.

The rapid conversion of land to urban and suburban areas has profoundly altered how water flows during and following storm events, putting higher volumes of water and more pollutants into the nation's rivers, lakes, and estuaries. These changes have degraded water quality and habitat in virtually every urban stream system. The Clean Water Act regulatory framework for addressing sewage and industrial wastes is not well suited to the more difficult problem of stormwater discharges. This book calls for an entirely new permitting structure that would put authority and accountability for stormwater discharges at the municipal level. A number of additional actions, such as conserving natural areas, reducing hard surface cover (e.g., roads and parking lots), and retrofitting urban areas with features that hold and treat stormwater, are recommended.

TMDLs (Total Maximum Daily Loading) define how much of a pollutant a water body can tolerate on a daily basis & still meet the relevant water quality standards. All of the sources of the pollutant in the watershed combined, including non-point sources, are limited to discharging no more than that total limit. EPA is suing states to force them to produce TMDLs. A growing number of California's water bodies are either subject to consent decrees to develop TMDLs, or are the subject of notices of intent to file lawsuits that may have that outcome. This report addresses California's many problems in establishing TMDLs for its impaired water bodies.

A third-party TMDL is a TMDL in which an organization or group other than the lead water quality agency takes responsibility for developing the TMDL document and supporting analysis. A third party can be a watershed group, municipal wastewater or stormwater discharger organization, industrial discharger entity, other unit of government (such as a county, city, municipality, or land management agency), or nonpoint source organization (such as a farm bureau, irrigation and drainage district, or landowner). Under a cooperative agreement with the U.S. Environmental Protection Agency, WEF has developed a Tool Kit for third-party TMDL development. Third parties are often very familiar with local watershed issues and can provide valuable insights to the TMDL process. The involvement and economic support of third parties can leverage state funds, as well as the resources and expertise of other agencies and nongovernmental organizations. Third-party involvment in TMDL decisions may improve the level of stakeholder support for the TMDL, increase the likelihood of effective implementation of pollutant controls, and increase the degree of public understanding of TMDLs and water quality protection issues.

Narrative water quality criteria are an integral component of States water quality standards but they pose special problems when incorporated into the TMDL process. The TMDL process is typically a quantitative activity, defining numeric allowable loads necessary to meet a numeric water quality objective. Narrative criteria confound development of quantitative TMDLs, due to the absence of these numeric criteria. The objective of this research was to improve the methods for addressing narrative water quality criteria in the TMDL process. The problems associated with narrative criteria in the TMDL process are known in general terms but, prior to this research, there has not been a thorough review of the use of narrative criteria in TMDLs nor broad guidance on how to address narrative criteria in the TMDL process. The approach taken for this research was to define the range of problems associated with all types of narrative criteria by means of a comprehensive review of 120 narrative TMDLs, and provide guiding principles to help address these problems.