SANITARY SEWER OVERFLOWS

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SANITARY SEWER OVERFLOWS

• 22st Annual
• U.S. EPA Region VI
• Pretreatment Association Workshop
• August 7-10, 2006
• Michael P. Carolan
• Special Services Division

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Sanitary Sewer Overflows (SSOs)
Whats on your menu?
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actually, why dont you make that order to go?!
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maybe a picnic isnt such a good idea either.
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Please?!?...please cancel that order of beans!
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On second thought, cancel it allI may never eat
again!
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Austin American-Statesman Headlines, August 1998
following the Brushy Creek Overflow
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Administrative Order from the U.S. EPA

• Issued April 29, 1999
• Compliance date December 31, 2009 (extension of
  2007 due date)
• Goal elimination of SSOs
• Penalty Provision - 32,500/ Day / Violation

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Causes of Reportable Spills 1/1/01 12/31/01
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The City of Austin Pretreatment Programs
Historical Approach to SSO Prevention

• Plan Review Grease Trap Sizing
• Surcharge Program
• Compliance Sampling Inspections
• SSO Response

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Plan Review Grease Trap Sizing

• FOG abundant in restaurant wastewater
• Major source of concern with SSOs
• Grease Trap is the last line of defense

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Plan Review Grease Trap Sizing
Overview of Grease Trap Operating Principals
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Plan Review Grease Trap Sizing
All kitchen fixtures in food-prep clean-up
areas should be plumbed to the trap. Such
as2 3-comp. sinks,prep sinks,dishwashers,
floor drains, trench drains, floor
sinks,garbage disposers,wok stoves,tilt
kettles. Hand sinks, mop sinks condensate
drains may bypass the trap.
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Plan Review Grease Trap Sizing
A very inefficient grease trap
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Plan Review Grease Trap Sizing
An even less efficient grease trap
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Plan Review Grease Trap Sizing

• Size Does Matter!
• Under-counter
• grease traps no
• longer approved
• Minimum sized
• trap 100 gallons
• Discourage use of garbage disposers or encourage
  their removal.
• Over sized trap may be just as problematic
  (stagnation, odor problems and/or corrosive
  conditions).

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Plan Review Grease Trap Sizing
The design is as important as the size. Note the
short distance between the inlet and outlet (no
longer approved for installation).
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Plan Review Grease Trap Sizing
Flow diverter on inlet side eliminates channeling
effects or short circuiting.
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Plan Review Grease Trap Sizing
Proper baffling key to even flow
distribution. External inverts less likely to be
broken.
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Surcharge Program

• Determined based
• on the quality of
• the wastewater
• discharged
• Potentially very
• expensive for major
• FOG dischargers
• High utility bills help to make compliance a top
  priority.
• Sampling frequency set based on flow and
  surcharge billing rate.

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Compliance Sampling Inspections

• Sites inspected during construction to ensure
  proper location of sample port.
• Once open for business, permitted as a general
  industrial user.
• Required to have on site 3 years of manifest
  records of grease interceptor maintenance.
• Addition sampling/inspections initiated based on
  threshold values from SC sampling for COD and/or
  TSS.
• Enforcement based on compliance with daily
  average limit based on four grabs.

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Compliance Sampling Inspections
The use of a sludge depth measuring device is not
only useful, its fun!
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Compliance Sampling Inspections
The key is to make sure that all kitchen waste is
handled in accordance with best management
practices.
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SSO Response

• Typically reported by line maintenance crews and
  utility dispatch office to Pretreatment Staff.
• Follow-up investigations conducted by
  Pretreatment Staff.
• Grease Traps inspected and manifest documentation
  reviewed.
• Enforcement actions taken as appropriate not
  usually criminal.

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Obstacles to Enforcement

• No minimum specified grease interceptor pump-out
  frequency
• FOG is a daily average limit (required at least
  4 grabs), labor intensive monitoring
• Manifest documentation not usually available
  (requirements in Health Ordinance)
• Poor internal communication between field crews,
  dispatch and pretreatment program
• Limited enforcement options (criminal enforcement
  options very labor intensive)
• Low level of public awareness of problem

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Pretreatment Program Improvements for SSO
Prevention

• Wastewater Discharge Ordinance Revision
• Improved Internal Communication
• Expanded Enforcement Option Menu
• Public Outreach Education

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Wastewater Discharge Ordinance Revision

• FOG limit changed to Instantaneous Maximum
  Allowable Limit.
• Grease trap pump-out required at least every 3
  months or when 50 or more of the wetted height
  of the grease interceptor, as measured from the
  bottom of the grease interceptor to the invert of
  the outlet pipe, contains grease and solids.
• May establish other cleaning requirements
  necessary to protect the POTW or a portion of the
  sanitary sewer.

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Improved Internal Communication

• Dispatch pages Pretreatment Group with all SSOs.
• Utility Investigator contacts Pretreatment Group
  if SSO grease related.
• Pretreatment Group paged if an IU/Multi-Family
  dwelling is involved in SSO.

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Expanded Enforcement Option Menu

• Special Billing
• Austin City Code has allowed the recovery of
  expenses incurred by the City relating to
  violations of pretreatment standards or
  requirements.
• Bill Industrial Users for SSO clean up, repair,
  and investigation work.

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Expanded Enforcement Option Menu

• Other Administrative Options
• Employ special permits or
• compliance schedules
• specifying pump-out
• frequency reporting
• requirements
• (manifest records).
• Pursue recovery of economic
• benefit (should be easy to
• calculate).

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Public Outreach Education

• Vastly Expanded Web-site Featuring
• Detailed program policy descriptions
• Applicable rules regulations (local, state
  fed.)
• A grease trap maintenance presentation (in
  English and Spanish)
• Tips for lowering surcharges utility bills
• A surcharge calculator
• Forms, applications reports
• Links to other pollution prevention resources
• Much, much more.
• To see for yourself, go to www.cityofaustin.org/p
  retreatment

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Public Outreach Education
Apartment Complex Door Hangers
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Public Outreach Education
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Public Outreach Education
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Public Outreach Education

• Water Week Festival every year for Schools and
  Civic Groups
• Demonstration for Boy- and Girl- Scouts

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Other Improvements In the Pipeline

• Assumed regulatory authority over local Liquid
  Waste Hauler Program.
• Redesigned Trip Ticket manifest forms for
  improved tracking of waste.
• Development of new database system, ultimate goal
  electronic tracking of compliance with pump-out
  requirements.

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Other Improvements In the Pipeline

• Redesigning Warning Citation.
• Planned increase in routine monitoring for
  compliance with pump-out and manifest
  documentation requirements.
• Part of effort to streamline enforcement
  procedures.

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Sanitary Sewer Overflows 1/1/01 12/31/05
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Sanitary Sewer Overflows 1/1/01 12/31/05
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Questions?

• Contact Information
• Michael P. Carolan
• Pretreatment Compliance Specialist, Sr.
• Special Services Division, Austin Water Utility
• 3907 S. Industrial Drive, Suite 100
• Austin, TX 78744-1040
• Phone [phone]
• Email michael.carolan_at_ci.austin.tx.us
• Visit our Program on the Web at
• cityofaustin.org/pretreatment