Today s talk: Review of efforts to control raw sewage discharges from municipalities Talk about our Measures of Success and how that has impacted our

Transcription

1 By Peter Ostlund MDNRE Water Resources Division

2 Today s talk: Review of efforts to control raw sewage discharges from municipalities Talk about our Measures of Success and how that has impacted our view on SSOs

3 Changes to our department s name DNR split to DNR & DEQ (~1995) DNR and DEQ combined to form DNRE (Jan 2010) DNRE split to DNR & DEQ (March 2011) Changes to our division s name SWQD combined with DW to form WD (~2002) Renamed WB (2004) WB split, and former SWQD programs joined with LWMD to create Water Resources Division (2010)

4 Separate Sanitary Overflows (SSO); History May 2000 A renewed strategy to identify SSOs and take regulatory action to eliminate identified SSOs. July 2000 Revised the law to require notification of all untreated and partially treated SSO discharges. Revised again Approximately 200 municipalities identified with SSOs.

5 Separate Sanitary Overflows (SSO); History December 2002 Issued SSO Policy after consultation with stakeholders (on website). October 2003 Issued SSO Policy Clarification Statement (on website).

6 SSO Policy Highlights SSOs to be eliminated or treated to federal secondary treatment standards, though total elimination may not be practical or economically feasible. Establishes a remedial design standard at the 25 yr- 24 hr storm, using growth conditions and normal soil moisture (or 1 discharge in 10 years in Clarification Statement). Corrective programs to be in legally enforceable documents, with phased short term and long term corrections, generally years in length.

7 SSO Policy Highlights (continued) SSOs are not authorized, but enforcement discretion considered for communities that are complying with enforceable programs. The Department conducts on-going assessment of the need for additional corrective programs based on reported SSOs.

8 Enforcement Orders (entered) , 22 new orders , 37 new orders , 15 new orders

9 In accordance with Part 31, we produced annual reports that describes what we were doing with the control of CSOs and SSOs. After a couple years of reporting, we started monitoring progress.

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11 CSO Control in Michigan number of untreated outfalls Time Lapse

12 CSO Control in Michigan volume discharged/year in MG 40,000 35,000 30,000 20,674 25,000 20,000 13,600 Total CSO Volume Untreated 15,000 31,726 23,802 27,148 9,422 Partially Treated 10,000 19,354 16,648 5,000 10,342 12,

13 CSO Control in Michigan Detroit s 050A outfall O50A Annual Flow (MG) Annual Discharge (MG) Year

14 CSO Control in Michigan volume discharged/year in MG

15 Measures of Success (for Water Bureau) Identify important outcomes Set goals for meeting outcomes Measure progress towards outcomes Align staff efforts/activities towards those outcomes Provide information to the public in an easy to understand format

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17 We set goals: Eliminate untreated sewage discharges The long-term combined sewer overflow (CSO) goal is complete elimination of untreated CSO discharges. For sanitary sewer overflow (SSO), the goal is to minimize untreated SSO discharges An interim goal is to reduce the volume of SSOs discharged annually, from approximately 58 million gallons in 2007 to less than 20 million gallons in 2020, due to events less than the 25-year, 24-hour storm.

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20 What happened? What is the increase in SSOs due to? Increase in large rain events Better reporting (new entities reporting) More failing systems Something else? Where to start?

21 Looked at last 10 years of data RELIABLE DATA

22 10 years of data ~4000 records to review Lack of consistent reporting (units, for instance) Change in how we re reporting data Data isn t stagnant Working with historic data is difficult and perhaps dangerous to my health!

23 working with ~4000 data points SSO Volumes Volume in Million Gal llons Annual Report Revised Values

24 The law requires reporting of partially or untreated discharge Initially we labeled everything an SSO or CSO. We realized that SSO or CSO didn t describe all the types of partially treated wastewaters. What is an SSO? For our current annual report, an SSO is anything that doesn t get treatment at and is discharge from a WWTP

25 WWTP Blending Blending is the act of bypassing part of the wastewater flow around a treatment unit because of wet-weather weather flow capacity issues In Michigan, there are less than 5 WWTPs authorized to blend under their NPDES permit DEQ uses the term blending only in response to wet weather events at these 5 permitted WWTPs These NPDES permits include requirements that move the WWTP to provide full treatment of all wastewater flows up to the 25-yr 24-hr storm

26 WWTP - Bypassing Sometimes in response to storm events (excessive I&I) Sometimes due to mechanical failure and lack of adequate backup Bypass Prohibition - Bypass is prohibited unless: bypass was unavoidable to prevent loss of life, personal injury, or severe property damage; there were no feasible alternatives to the bypass, such as..; the permittee submitted notices as required

27 What we learned by measuring is that we may not be measuring what we need to measure.

28 working with ~4000 data points SSO Volumes Volume in Million Gal llons Annual Report Revised Values

29 SSO Voumes total volume precipitation related Volume- Million Gallons

30 Calendar Year Revised Values Precipitation Related No Precipitation totals

31 Number of Events Cal Year unspecified <100 <1000 <10000 < <1 MG <10 MG >10 MG total totals

32 Grand Rapids Lansing Detroit

33 In calendar year 2008, there were two intense runoff events September (9/13-9/27) - 74 events, with start dates from 9/13-9/22 - Total volume: 62.5 MG December (12/27-12/31) - 41 events, with start dates from 12/27-12/29 - Total volume: MG SSO discharges not associated with those two events for calendar year 2008 is MG.

34 2009 SSO discharge volume associated with the four intense runoff events in 2009 was MG and the 2009 volume not associated with extreme weather events was approximately 97 MG.

35 working with ~4000 data points SSO Volumes Volume in Million Gal llons Annual Report Revised Values

36 In the last 3 years: 843 million gallons of SSO discharged 4 entities appear to account for 68% of this volume The next 4 entities appear to account for 7% of this volume Most of these are under enforcement programs Mixed bag of causes: large storms, better reporting, and failing infrastructure

37 Back to Measures of Success, what should we measure, what makes sense? SSOs from events that exceed the design storm shouldn t be counted in our measures of success, we can t control the rain! Focus on SSOs from storms less than the design storm and SSOs from non-precipitation events We re modifying our report form, database, and routine evaluations to allow this analysis.

38 Dry Weather SSOs Dry Weather SSOs

39 Type of Discharge Being Reported RTB Discharge: The reported discharge is from a retention and treatment basin (or equivalent structure) that serves a municipal combined sewer system. The RTB or equivalent structure is designed in accordance with approved plans and operated in accordance with criteria in a permit, order, or other enforceable document issued by the Michigan Department of Natural Resources and Environment (DNRE) or by court action. This type of discharge is commonly referred to as a RTB discharge. CSO Discharge: The reported discharge is from a municipal combined sewer system and is not from a facility that is designed to meet final performance criteria specified in a permit, order, or other enforceable document. The discharge is associated with wet weather events. This type of discharge is commonly referred to as a combined sewer overflow (CSO). SSO Discharge: The reported discharge is from a private or municipal separate sewer collection system (not wastewater treatment plant) during wet or dry weather, or a dry weather discharge from a municipal combined sewer collection system. This type of discharge is commonly referred to as a sanitary sewer overflow (SSO). Other: The reported discharge is of untreated or partially treated sewage (definition in Section 3112a) that is not characterized by one of the conditions listed above. A detailed description of the discharge is provided below.

40 We all need to educate the public, media and regulated/regulators, and change the dialogue regarding CSO and SSO control Examples of not understanding: Saginaw Bay muck For CSO control, RTBs are an acceptable final outcome Some states are planning to eliminate SSOs or don t have SSOs

41 In conclusion We still have work to do to identify what s happening in the SSO world. Need to focus our efforts where we can make a difference Constantly evaluating our approach to protect public health and the environment, and make best use of our limited resources

42 Peter Ostlund Field Operations Section Chief Water Resources Division