1. Wastewater Facilities Upgrade Project
Novato Sanitary District
Wastewater Facilities Upgrade Project
Water and Environment

2. Background 2005 Novato Sanitary District had two treatment plants
Novato Plant: million gallons/day
Ignacio Plant: million gallons/day
Peak wet weather flows = 7 times average flow
All treatment components over 20 years old
Majority of components are 30 to 50 years old
Some facilities have been reused three times
Plant had reliability issues
Additional flow and load was forecasted
More stringent regulations were coming

3. Novato treatment plant

4. Novato Treatment Plant 3.6 million gallons/day

5. Ignacio treatment plant

6. Ignacio Treatment Plant 1.6 million gallons/day

7. Existing Plants Had Difficulty Meeting Previous NPDES Limits and …
No. of Violations

8. …Regulatory Requirements Were Getting Stricter
New “zero spill” tolerance requirement
Zero exceedance of effluent limitations
Mandatory fines for each exceedance (SB709)
District under mandatory time schedule for upgrades (March )
Reduction in discharge limits for mercury, cyanide and others
Ignacio must meet full secondary treatment
EPA and RWQCB were ambiguous but worrisome regarding ‘blending’

9. Permit Conditions Vary Based on Discharge Location
Season
Permit Condition
Operational Mode
Reclamation - Summer
June thru August
BOD mg/L
Carbonaceous
Bay Discharge –
Spring and Fall
May, Sept, Oct
BOD mg/L
TSS mg/L
NH mg-N/L
Nitrification
Bay Discharge - Winter
November thru April
BOD mg/L
TSS mg/L
Note that these are average monthly values.

10. Condition Assessment Conducted on All Plant Components

11. Many Plant Areas Were Not Reusable

12. Several Alternatives Were Considered
Replace both treatment plants
Consolidate treatment at one plant
Novato site
Ignacio site
Type of treatment process
Oxidation ditch
Activated Sludge (MLE)
MBR
Consolidation at Novato with Activated Sludge recommended
Lowest cost
Highest reliability
Lowest environmental impact

13. New Consolidated Treatment Plant
Ignacio Transfer PS
and Equalization Basins

14. Construction Cost Summary of Total Project
Item
Construction Estimate
$ million*
Construction Bid
$million
Novato Treatment Plant 75 67
Ignacio PS + FM 12 11
Total 87 78
*Escalated to mid pt of construction

15. Flow Path, New Treatment Plant
From
Collection System
Ignacio PS
To Reclamation or
Outfall

16. New Consolidated Plant
Aeration
4 X 115,000 cu ft basins
Anoxic zones
Primary Clarifiers
2 X 100 ft diameter, covered tanks
Headworks
2 X Aquaguard Screens, 15 mm opening
2 X Vortex grit chambers
Influent PS
6 X 9.4 MGD Submersible Pumps
Secondary Clarifiers
2 X 125 ft diameter
UV Disinfection
3 Channels

17. Innovative Aeration Design Avoids Flow Equalization and Blending
Summer conditions require only carbonaceous removal
Designed to avoid nitrification to save energy
Winter conditions:
Permit requires nitrification for Bay discharge
Peak wet weather flows up to 7 times average
Design of dual mode aeration avoids need to equalize peak flows
Conventional MLE operation up to 18 MGD
Transition to contact stabilization 18 to 47 MGD

18. Nitrification Mode Winter Flow < 18 MGD
Primary Effluent
ZONE F
AERATED
ZONE E
AERATED
Aeration
Basin 3
ZONE A
ZONE B
ZONE C
ZONE D
AERATED
RAS
Aeration
Basin 4

19. Contact Stabilization Mode: Winter Flow at > 18 MGD
ZONE F
AERATED
ZONE E
AERATED
Primary Effluent
ZONE A
ZONE B
ZONE C
ZONE D
AERATED
RAS

20. Cost Saving Measures Totaled $17 million
Item
Savings, $ millions
Innovative method to treat peak wet weather flows
3.0
Postponement of third secondary clarifier
4.1
Reuse of existing emergency generators
1.5
Reuse of existing diesel pumps at effluent pump station
1.0
Deletion of parallel force main
2.4
State Revolving Fund low interest loan
5.5*
*Present worth of interest savings

21. Annual Energy Savings Came From Many Sources
Design Element
Net Annual
Savings, kWh
Net Annual Power Savings, $
Utility Water Discharge Pressure
30,400
$3,950
Plant Elevation
30,800
$4,000
Submerged Weirs at Peak Flows
38,450
$5,000
Premium Efficiency Motors
83,000
$10,800
Aeration Basin Depth
85,750
$11,150
Energy Efficient Blowers
310,000
$40,250
NSD Annual Total Savings
528,000
$76,000
Present Worth of Savings, 30 yrs, 5%
$1,200,000
Typical Annual Energy for AS Plant** 3,394,500 $441,285 at 1,200 kwh/MG and $0.13 electrical cost

22. Plant is in Start-up, and Performing Well
Parameter
Units
Average Monthly
Nov - Apr
May, Sept, Oct
Typical Performance of New Plant
BOD5
mg/l 30 15
5 to 10
TSS 10
3 to 6
Ammonia 6
<1
Oil and Grease
Mg/l 5
< 5
Enterococcus
Per 100 ml 35
< 10 to 15
Fecal Coliform
MPN
140
4 to 8

23. Thank you