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
No information was provided by the United States government regarding wastewater
infrastructure (Figure 3) for most United States Areas of Concern. Data was
for the United States Detroit River and Milwaukee Estuary Areas of Concern,
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,
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
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