11th Biennial Report on Great Lakes Water Quality


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Chapter 3

Introduction

Contaminated Sediment

Funding for Sediment Remediation

Wastewater Infrastructure Maintenance and Upgrades

Fish and Wildlife Habitat

Waste Sites and Nonpoint Source Pollution

Accountability and Responsibility for Remedial Action Plans

United States Approach

Canadian Approach

Community-based Alliances

Confirming the Status of Restoration Efforts

Keeping the Focus on Beneficial Uses

Funding for Remediation and Planning Efforts

Corporate/Private Spending on Remediation

 

Progress Toward Restoration

Wastewater Infrastructure Maintenance and Upgrades

The maintenance of and improvements to sewage treatment plants and wastewater infrastructure, together with the need to reduce sanitary sewer and combined sewer overflows, represent a costly challenge in many Areas of Concern (see Box 7). Although such maintenance and improvements are essentially a municipal or regional responsibility, funding can come from higher levels of government, depending in part on the ability of the municipal government to finance the improvements.

No information was provided by the United States government regarding wastewater infrastructure (Figure 3) for most United States Areas of Concern. Data was available for the United States Detroit River and Milwaukee Estuary Areas of Concern, where $1 billion (USD) and $2.2 billion (USD), respectively, already have been invested in upgrading wastewater infrastructure. According to the United States government, these two Areas of Concern have a remaining need of at least $2.4 billion (USD) and $1 billion (USD), respectively, to complete the upgrade of their wastewater systems, and the Cuyahoga River Area of Concern (Cleveland, Ohio) has a remaining need of $1 billion (USD). No other information was available regarding the amount already spent or the amount needed to be spent to complete upgrades necessary to restore beneficial usesd.

    Figure 3 :
    Status of Wastewater Infrastructure Investments.
    (Click on the picture for a larger version).

Approximately $270 million (CAD) has been spent over the past 10 years by federal and provincial governments for wastewater infrastructure improvements in Canadian Areas of Concern. Environment Canada notes that remaining wastewater infrastructure improvements across Canadian Areas of Concern will require approximately $1.8 billion (Cdn.). The Hamilton Harbour Area of Concern alone has an estimated need of $545-$600 million (CAD).

 
Box 7 :
Wastewater Treatment and Discharges to the Great Lakes

Depending on the extent to which wastewater is purified, sewage treatment is classified as primary, secondary or tertiary. Primary treatment removes floating and heavier suspended solids but does not reduce the concentration of soluble nutrients such as phosphorus. In seven Ontario Areas of Concern some municipalities have primary treatment plants.

Secondary treatment uses biological methods in which bacteria break down the dissolved organic matter. The wastewater is then allowed further settling to remove particles. Metal salts are added to remove phosphorus. With tertiary or advanced wastewater treatment, all but a negligible amount of bacteria and organic matter can be removed. Sand filters or additional basins can be used to improve the quality of treated water released. Dechlorination is sometimes needed to minimize environmental impacts. Secondary treatment is the general treatment standard in the Great Lakes.

Although the quality of effluent discharged by most sewage treatment plants in the Great Lakes basin has greatly improved, combined sewer and sanitary sewer overflows continue to severely degrade the waters near many urban Areas of Concern. Combined sewers were designed to carry both raw sewage and storm water to sewage treatment plants. Overflows of untreated water and sewage occur during or after severe storm events and are discharged directly into the waterways. Sanitary sewer overflows are discharges of raw or inadequately treated sewage from separate sanitary sewer systems. Industrial waste that has been discharged to the sewer system also can be present in these overflows.

Such overflows often result in beach closings because of bacterial pollution. They can also affect the quality of drinking water and can cause excessive growth of aquatic plants. Costs associated with even partial treatment are considerable. For example, even though the cost of a deep tunnel system in Milwaukee exceeded $2 billion (USD), an estimated 49.2 billion litres (13 billion gallons) of untreated wastewater has been released since the project was completed13,14.