https://www.americancityandcounty.com/wp-content/themes/acc_child/assets/images/logo/footer-logo.png
  • Home
  • Co-op Solutions
  • Hybrid Work
  • Commentaries
  • News
  • In-Depth
  • Multimedia
    • Back
    • Podcast
  • Resources & Events
    • Back
    • Resources
    • Webinars
    • White Papers
    • IWCE 2022
    • How to Contribute
    • Municipal Cost Index – Archive
    • Equipment Watch Page
    • American City & County Awards
  • About Us
    • Back
    • About Us
    • Contact Us
    • Advertise
    • Privacy Statement
    • Terms of Service
American City and County
  • NEWSLETTER
  • Home
  • Co-op Solutions
  • Hybrid Work
  • Commentaries
  • News
  • In-Depth
  • Multimedia
    • Back
    • Podcasts
  • Resources/Events
    • Back
    • Webinars
    • White Papers/eBooks
    • IWCE 2022
    • How to Contribute
    • American City & County Awards
    • Municipal Cost Index
    • Equipment Watch Page
  • About Us
    • Back
    • About Us
    • Contact Us
    • Advertise
    • Cookie Policy
    • Privacy Stament
    • Terms of Service
  • newsletter
  • Administration
  • Economy & Finance
  • Procurement
  • Public Safety
  • Public Works & Utilities
  • Smart Cities & Technology
  • Magazine
acc.com


CSO control is no longer mere engineering

CSO control is no longer mere engineering

When water pollution caused beach closings at Lake St. Clair, north of Detroit, public attention focused on the problems of urban water management and
  • Written by Kaufman, Marty; Marsh, William
  • 1st February 1995

When water pollution caused beach closings at Lake St. Clair, north of Detroit, public attention focused on the problems of urban water management and the combined sewer over-flow (CSO) issue.

The River Rouge basin, south of Lake St. Clair, has experienced severe pollution problems in the recent past. The river’s water quality has been so degraded that it is listed by the Michigan Department of Natural Resources as one of the most toxic sites in the state — 28th out of 2,700 sites in a 1994 survey conducted by the department.

Fecal coliform is the biggest water quality problem; eighty-six percent of samples taken in 1987-1988 exceeded the accepted water quality standard, and there were significant dissolved oxygen and total solids violations.

The Rouge CSO problem is not unique. But proposed solutions, which involve a combination of engineering, public policy changes, land-use modification and community action, represent a break from traditional control methods that are both innovative and adaptable to individual communities.

These control methods involve a variety of non-structural and structural alternatives. In Portland, Maine, for instance, a proposed plan calls for industrial pretreatment to remove pollutants at the source. It includes street sweeping, sewer cleaning and flow control using vortex valves.

The plan incorporates watershed management techniques, such as wetlands construction, the use of planted grassed-in areas and construction of retention basins, although this accounts for less than one-fourth of the total plan cost.

Indeed, as the 1993 floods in the Midwest demonstrated, the days of relying purely on engineering solutions to water management problems are over. At Lake St. Clair, the diversity of the Rouge watershed ensures that no single formula for water management is appropriate for all parts of the basin. Thus, any approach to the problem must begin with a thorough analysis of the watershed’s physiography — soils, slopes, vegetation and water features– and land-use impacts of stream hydrology, including baseflow (groundwater contributions), overland flow and stormwater loading.

The resolution of the CSO issue is being presented as a tradeoff between retention basins and sewer separation, although neither alternative considers source reduction — decreasing the amount of water released to sanitary and storm sewers by using low-flush toilets, disconnecting downspouts from storm drains and increasing stormwater retention.

Under a proposed plan, 10 or more additional basins will be constructed in southeastern Michigan at a cost of an estimated $1 billion. In addition to the cost, the plan may be handicapped by the availability of land; CSO retention basins have not been and cannot be sized to accommodate all storms.

Storm magnitude and frequency is another problem with the basin approach. Currently, two trends in the Rouge watershed are producing large 10-year runoffs. First, continued land, use development and the construction of roads, sidewalks and other impervious surfaces are generating more runoff per rainstorm.

And, since 1960 there has been significant land-use development in the Rouge basin through expansion into vacant lands and the infilling and reuse of existing urban lands. Consequently, the size of the 10-year storm in terms of stormwater added to the sewer system is getting larger.

Also, the magnitude and frequency of rainstorms in southeastern Michigan are increasing with urban development, a trend documented by the Southeast Michigan Council of Governments. By the time basins are completed in 2005, physical conditions within the watershed may well have changed significantly, and more and bigger basins will be needed.

A new approach to the overflow problem must consider ecological, behavioral, economic, legal and geographical factors and involve longterm planning. Stormwater management should accommodate the entire spectrum of stormwater and sewage flows, including the volumes produced, the amounts discarded from properties and the rates at which stormwater and wastewater are delivered to streams.

Tags:

Most Recent


  • Report: Local and state governments are facing a retention crisis; the worst could be yet to come
    When the pandemic struck in 2020, public retention was hit hard: jobs in local government plummeted by 8.5 percent; state employment dropped by 4.4 percent. Two years later, local and state government jobs have rebounded by about half—to 4.1 and 1.9 percent below pre-pandemic levels respectively, according to a new report from Mission Square Research […]
  • Amid an unprecedented increase in federal spending, cities and counties stand to benefit from partnerships
    The so-called “American dream” of upward mobility has more or less stagnated: Today, a little more than 40 percent of children raised at the bottom of the income ladder remain there as adults, according to Pew Charitable Trusts, and only half grow up to earn more than their parents. This data points to a concerning […]
  • hybrid technology
    Governments using technology to harness data and improve decision-making
    There’s one kind of technology that state and local governments covet, says Rob Carey, president of Cloudera Government Solutions. “While supporting multiple state and local government agencies, our team has noticed an increase in the need for hybrid cloud solutions.” A hybrid cloud is the combination of both public and private cloud deployment models. In […]
  • Seattle-Tacoma-Bellevue, WA
    Infrastructure highlighted by city leaders as top priority in analysis of 60 mayoral addresses
    After two years of ping-pong lockdown orders, mask mandates, unprecedented vaccine drives and economic uncertainty, cities across the United States are beginning to emerge in the pandemic’s aftermath, and they’re prioritizing infrastructure, according to a report published Wednesday by the National League of Cities (NLC).  “The new normal, as we now understand it, is here,” […]

Leave a comment Cancel reply

-or-

Log in with your American City and County account

Alternatively, post a comment by completing the form below:

Your email address will not be published. Required fields are marked *

Related Content

  • Lessons from your friendly neighborhood public service employees
  • North Texas alliance partners with Marketplace.city on smart government solutions
  • Harris County deploys next-generation security in 150 public buildings
  • Public procurement can be transformative for stakeholders in a community

White papers


How to Assemble a Rockstar Website Redesign Steering Committee

7th June 2022

Hand Hygiene: Compliance Matters

23rd May 2022

What it Takes to Build a Winning Esports Program

23rd May 2022
view all

Events


PODCAST


Young Leaders Episode 4 – Cyril Jefferson – City Councilman, High Point, North Carolina

13th October 2020

Young Leaders Episode 3 – Shannon Hardin – City Council President, Columbus, Ohio

27th July 2020

Young Leaders Episode 2 – Christian Williams – Development Services Planner, Goodyear, Ariz.

1st July 2020
view all

Twitter


AmerCityCounty

Report: Local and state governments are facing a retention crisis; the worst could be yet to come dlvr.it/SSnmS7

24th June 2022
AmerCityCounty

Amid an unprecedented increase in federal spending, cities and counties stand to benefit from partnerships dlvr.it/SSkGBn

23rd June 2022
AmerCityCounty

Governments using technology to harness data and improve decision-making dlvr.it/SSk3H0

23rd June 2022
AmerCityCounty

Infrastructure highlighted by city leaders as top priority in analysis of 60 mayoral addresses dlvr.it/SSgBck

22nd June 2022
AmerCityCounty

Oklahoma City puts the focus on employees when implementing changes in office technology dlvr.it/SSfyns

22nd June 2022
AmerCityCounty

We want to hear from you! Please take this brief survey and let us know how your organization is managing your budg… twitter.com/i/web/status/1…

22nd June 2022
AmerCityCounty

Buying smart solutions: Technology is now part of (almost) every government purchase dlvr.it/SSbj3Z

21st June 2022
AmerCityCounty

Amid tech labor shortage, outsourcing digital services could provide relief dlvr.it/SSbj23

21st June 2022

Newsletters

Sign up for American City & County’s newsletters to receive regular news and information updates about local governments.

Resale Insights Dashboard

The Resale Insights Dashboard provides model-level data for the entire used equipment market to help you save time and money.

Municipal Cost Index

Updated monthly since 1978, our exclusive Municipal Cost Index shows the effects of inflation on the cost of providing municipal services

Media Kit and Advertising

Want to reach our digital audience? Learn more here.

DISCOVER MORE FROM INFORMA TECH

  • IWCE’s Urgent Communications
  • IWCE Expo

WORKING WITH US

  • About Us
  • Contact Us

FOLLOW American City and County ON SOCIAL

  • Privacy
  • CCPA: “Do Not Sell My Data”
  • Cookies Policy
  • Terms
Copyright © 2022 Informa PLC. Informa PLC is registered in England and Wales with company number 8860726 whose registered and Head office is 5 Howick Place, London, SW1P 1WG.
This website uses cookies, including third party ones, to allow for analysis of how people use our website in order to improve your experience and our services. By continuing to use our website, you agree to the use of such cookies. Click here for more information on our Cookie Policy and Privacy Policy.
X