Wastewater Background

1
Wastewater Background

• May 2004

2
Outline

• 1983 WWTP
• 1991 WWTP
• 1995-1999 History
• 2000-2003 History
• 2003-2004 History
• Unmet Needs for 1991 WWTP
• Upgrades to 1991 WWTP

3
1983 WWTP

• Secondary Treatment
• Comminutor (Grinder)
• Aeration Basin
• Oxidation Ponds
• Chlorine Injection
• Treatment Capacity of 0.83 MGD
• Adequate Disposal Capacity of 0.83 MGD in Summer
• Winter Season Discharge to Laguna Creek

4
1991 WWTP

• Secondary Treatment
• Headworks
• Oxidation Ditches
• Secondary Clarifiers
• Chlorine Contact Chamber
• Return Sludge and Waste Sludge (Lagoon)
• Treatment Capacity 3.0 MGD
• Winter Season Discharge to Laguna Creek
• Inadequate Land Disposal Capacity for 3.0 MGD
• Bond for 9.77M

5
1995-1999 History

• 1996 Land Capacity Reached
• 7/97 City Receives New NPDES Permit (No Major
  Changes Compared to 1991 NPDES Permit)
• 1998 30 acres of Sludge Injection Field
  Converted to Irrigation and Brought On-Line
• 7/99 Inspection by Regional Board No Violations

6
2000-2003 History

• 7/00 Started New Master Plan for Existing WWTP
• 7/00 City Received NOV from Regional Board
• Cited Lack of Disposal Capacity
• All Other Violations Resolved
• 6/01 City Received NOV from Regional Board
• Cited Lack of Disposal Capacity
• All Other Violations Resolved
• 7/01 Direction by Council to Acquire Additional
  Land
• 7/01 Began Evaluation of Parcels for
  Acquisition

7
2000-2003 History (cont)

• 11/01 Submitted Report of Waste Discharge for
  New NPDES Permit
• 2/02 Presented Offers to Roman Catholic Bishop
  and Twin Cities Business Park
• 4/02 Offers Rejected
• 6/02 Began Condemnation of RCB Property
• 9/02 Judge Dismisses Condemnation
• 1/03 City Receives Building Moratorium
• 3/03 Council Decides Against Condemnation and
  Leases RCB Property
• 3/03 Regional Board Rescinds Building
  Moratorium Upon Signed Lease

8
2003-2004 History

• 1/03 and 12/03 City Receives First Tentative
  NPDES Permit and Second Tentative NPDES Permit
• 1/04 Regional Board Adopts NPDES Permit (Major
  Changes Compared to 1997 NPDES Permit)
• 3/04 City Appeals Many Provisions of New Permit
• 4/04 Stay Denied New NPDES Permit Takes
  Effect
• 4/04 New NPDES Permit Limits Storage Capacity
  of Reservoir (Summer Capacity Reduced by 2 Years)
• 5/04 City Begins Evaluation of Land for
  Additional Disposal Capacity

9
Unmet Needs for 1991 WWTP

• No Grit Removal
• Inadequate Land Disposal Capacity
• Existing Control Building Not Connected to New
  Plant
• Clay-lined Auxiliary Basin Serving as Bypass

10
Upgrades to 1991 WWTP

• Additional 210 Acres Added
• Control Building Plumbed Into New Plant
• Lift Station Constructed (for Control Building
  and Return from Auxiliary Basin)
• Pipe from Headworks Stubbed Out for Connection
  to Auxiliary Basin
• Lining of Auxiliary Basin Planned for FY2005

11
Summary

• Secondary Treatment Plant 3.0 MGD
• Still Owe on Construction Bond
• Onerous NPDES Permit Requiring Advance Treatment
  Pending Appeal
• Shortage of Land for Dry Season Disposal
• Lease for 180 Acres until 2008 (extend 2010)