1. Fats, Oil and Grease (FOG) Control
Aloha
Fats, Oil and Grease (FOG) Control
James Baginski, P.E.
James Baginski Enterprises
731 Kokomo Place
Honolulu, Hawaii (808)

2. MISSION: Maintain a Pristine Environment
Comply with Federal Clean Water Act

3. One of the Major Problems - Sanitary Sewer Overflows (SSOs)

4. One of the Major Causes - Grease Blockages in Sewer Pipes
Inside view of sewer pipes

5. Grease Blockage Sources
Restaurants & Food Processing Facilities

6. Regulatory Control Pretreatment Program

7. Typical Grease Interceptor Design
Method of Control
Typical Grease Interceptor Design

8. Honolulu Wastewater System
Number of Treatment Plants
Number of Pump Stations
Total Design Flow (mgd) 8 72
120
Collection System - approximately 2,000 miles of sewer lines
Honolulu population is about 800,000.

9. Compliance Background
1982 Honolulu’s Pretreatment Program Approved by EPA
1990 EPA issues Findings of Violations to Honolulu (related to SSO’s)
1995 Honolulu enters into Consent Agreement with EPA
1999 GI retrofit program begins; 90 grease related SSO’s = 36% of total annual SSO’s.
% of facilities retrofitted; 46 grease related SSO’s = 23% of total annual SSO’s.

10. Collection System Maintenance & Historical Data

11. Collection System Maintenance
Infrastructure Efforts to control FOG
Repair collection system conditions which promote grease blockages (e.g. line sag, surcharge conditions, pipe cracks/breaks, root intrusion).
Modify collection system standards to accommodate grease (e.g. seamless pipe, increased slope, larger pipe).
Conduct effective preventive maintenance program (i.e. identify and target “hot spots”).
Report chronic FOG problem areas or dischargers to the Pretreatment Program for enforcement.
Maintain detailed and accurate records of system condition.

12. Collection System Historical Data
Areas with Low Percentage of Retrofitted GIs
LOCATION
1999
2000
2001
2002
% of GIs upgraded
% of records indicating heavy grease in line
KALAKAUA 0%
12%
67%
100%
KAPIOLANI 4% 9%
92%
82%
AUAHI 5%
11%
ALA MOANA 6%
Approximately 20% of businesses requiring a GI have been retrofitted.

13. Collection System Historical Data
Areas with Higher Percentage of Retrofitted GIs
LOCATION
1999
2000
2001
2002
% of GIs upgraded
% of records indicating heavy grease in line
BERETANIA 0%
12%
21%
96%
100%
23%
22%
KAM HWY
10%
15%
20%
75%
50%
KALAKAUA 5%
25% 8%
33%
84%
80%
35%
14%
Approximately 20% of businesses requiring a GI have been retrofitted.

14. Collection System Historical Data
Pipe Cleaning and Spill Records:
Year
Miles of Pipes Cleaned
Number of Wastewater Spills
Number of Grease Related Spills *
Grease Spills as a Percentage of Total Spills
1995
343
268 73
27%
1996
406
332 95
29%
1997
401
310 88
28%
1998
558
231 63
27 %
1999 **
891
252 90
36 %
2000
658
263 86
33 %
2001
675
240
30%
2002
707
199 46
23%
* Grease was primary cause of spill
** Began GI retrofits in June (20% Complete)

15. Collection System Historical Data
Sand Island WWTP Data:
Year
Flow (mgd)
Influent O&G (mg/l)
Grease Spills
1995
75.935
44.2 73
1996
75.623
37.2 95
1997
77.047
27.7 88
1998
73.462
28.5 * 63
1999
73.917
22.5 90
2000
72.654
25.3 86
2001
70.664
24.5
2002
69.559
24.2 46
Reduction %
10%
45%
48%
* O&G analytical method changed from to 1664A (freon to hexane) in November 1998, as well as, new NPDES permit required increased monitoring frequency from 1/week to 3/week.

16. Pretreatment Program

17. Pretreatment Program Research Findings:
Many Fats, Oil and Grease (FOG) Sources are Not Connected to a GI (Pre-rinse garbage disposals).
Existing Grease Interceptors (GI) are “Inadequate”.
How do you determine what is adequate?

18. Consider…Stokes’ Law:
Pretreatment Program
Consider…Stokes’ Law:
Vr = g/18ν [S.G.w – S.G.o] x D²
Where:
Vr – rising velocity of the oil particle (cm/sec)
g – gravity constant (980 cm/sec²)
ν – viscosity of water in poises (0.01)
S.G.w – specific gravity or density of water (gm/cm³)
S.G.o – specific gravity or density of oil (gm/cm³)
D - diameter of the oil droplet (cm)

19. Factors Affecting FOG Separation:
Pretreatment Program
Factors Affecting FOG Separation:
Temperature – the less viscous the fluid (higher temp.), the faster the particle rise rate. However, too high temp. promotes emulsification.
Specific Gravity - The greater the differential specific gravity or density between the fluid and the particle, the faster the rise rate.
Diameter – The larger the particle diameter the faster the particle rise rate.

20. Oil Globule Rise Times for 3 inches @ 68 F:
Pretreatment Program
Oil Globule Rise Times for 3 68 F:
Diameter
[microns]
Rise Time (S.G.=0.9) [hr:min:sec]
300
0:00:15
125
0:01:27 60
0:06:36 40
0:14:24 20
0:58:08
10 (colloidal)
3:52:33 1
387:35:49
Table info from American Petroleum Institute Publication FOG S.G. range =

21. Pretreatment Program Retention Time Does Size Matter??
YEAH BABY, YEAH!!
Grease Interceptors must be sized to promote the adequate separation of FOG from wastewater. An important factor to consider is………..
Retention Time

22. Pretreatment Program GI Sizing Criteria
Minimum Grease Interceptor Volume (Vmin) is
determined using Retention Time (R), Storage
Factor (S) and Flow Rate (F).
or, V(min) = R x S x F
R = 30 Minutes
S = (25% Allowance)
F = Maximum Flow Rate Entering the GI (gpm)
where,

23. Pretreatment Program GI Sizing Criteria
V (min) = 30 x 1.25 x F
F - Flow rate is determined based on Drainage Fixture Units (DFU)

24. Pretreatment Program GI Sizing Criteria
Flow Rate
No. of Drainage Fixture Units  40
* F = (0.7 x DFU)
No. of Drainage Fixture Units  40
* F = (0.2 x DFU) + 20
DFU’s based on the Uniform Plumbing Code, 1997 edition, Table 7-3: Drainage Fixture Unit Values, Section Maximum Trap Loading, or Table 7-4: Discharge Capacity (gpm) for Intermittent Flow Only.
* “Piping Handbook, 7th Edition”, Muhinder L. Nayyar, McGraw-Hill;
Tables C13.3 & C13.4 on pages C.690 & C.691.

25. Hotel with Kitchen and Restaurant
Pretreatment Program
Comparison of Grease Interceptor Sizing Criteria
UPC Appendix H
1999 Honolulu Criteria
(Denver Based)
2001 Honolulu Criteria
Type of Facility
Calculated Size
Tank Requirement
Chinese Restaurant
6,000
2 x 3,000
1,125
1,500
885
1,000
Seafood Restaurant
2,088
3,000
1,080
Fine Dining
16,500
3 x 5,000 +
3,275
4,000
1,390
Hotel with Kitchen and Restaurant
3,500
1,688
2,000
1,050
Dinner Theatre (Luau)
7,500
2 x 4,000
2,500
919
Large Restaurant
10,320
2 x 5,000 +
3,225
2,520
Medium Restaurant
2,100
1,531
1,208
Small Restaurant
375
500
750
456

26. HONOLULU SIZED GREASE INTERCEPTOR
Pretreatment Program
HONOLULU SIZED GREASE INTERCEPTOR
SAMPLING RESULTS
Number of GIs sampled - 45
Number of samples taken - 90
Average Oil & Grease
Effluent Concentration (Avg) mg/l
pH (min) (avg) (max) 7
Temp. (degrees F) (min) 69º (avg) 86.6º (max) 105º
(Melting Point of Tallow (i.e. animal fat) degees F)

27. Pretreatment Program GI Maintenance Requirements
25% RULE
Storage factor used to determine GI maintenance frequency consisting of surface FOG material and settled solids.
PUMP-IN-FULL
Insure all solids are removed.
Inspect the GI for corrosion damage or cracks.
Enables “cradle-to-grave” tracking of FOG waste.

28. FOG Control Success Factors

29. FOG Control Success Factors
Consistent Facility Compliance Evaluations
Persistent/Consistent Enforcement Actions
Plan Reviews to verify Compliance with GI Program
Database Tracking and Follow-up
Program Implementation Strategy
Economic Considerations
Public Outreach and Education

30. FOG Control Success Factors
Program Implementation Strategy!
Understand the Political Environment – Votes.
Understand the Media – Stay 2 steps ahead. Create a “No Story” situation.
Involve the Industry – Raise awareness by meeting with Stakeholders (Property Owners, Restaurant Owners, Area Organizations/ Committees, Trade and Business Associations, City and Elected Officials).
Think “Money” - Businesses focus is on $. Find a way to merge environment and regulations. Build partnerships with the “Big Dogs”.

31. FOG Control Success Factors
Economic Considerations:
Project coordination & funding by property owners:
Property owners and tenants equally liable under most Ordinances.
Owners finance improvements and renegotiate tenant leases.
Tenants pay only their fair share while they are there.
Shared Grease Interceptors
Mixed Waste (kitchen/domestic) Grease Interceptors. [Currently 2 operating in Hawaii with more proposed]
Grant easements where space is limited.
ADDITIVES - Biologicals Only…No Enzymes or Surfactants.

32. FOG Control Success Factors
Public Outreach and Education
Public Info Meetings, Community/Industry Events
Brochures, Bus Posters
Educational Videos/Public Service Anouncements (Show Video)

33. Contact Information
James Baginski, P.E.
President
James Baginski Enterprises
731 Kokomo Place
Honolulu, Hawaii
Tel: (808)

34. Aloha and Mahalo
Questions?