Transcript Document
Water Services National
Training Group
Outcome Awareness Day
24th March 2009
Collaborative Study on Fats, Oil and Greases in
Drain and Sewer Systems
Midleton FOG Project
Sam Crowley B.E. (Civil)
Project Engineer, Response Engineering
M. Eng. Sc. Student
Civil & Env. Eng. UCC (Prof. G. Kiely, Supervisor)
Collaborative Study on Fats, Oil and Greases in
Drain and Sewer Systems
Midleton FOG Project
Midleton, Co. Cork
History of FOG related problems.
Population: 9,019
There are 63 FOG generators in Midleton.
€68,372 spent in 2005 including cleaning of pumping
stations €39,687 of this for FOG related work.
Approximately 58% of total spent on drain cleaning.
Methodology
FOG Hotspots
1.
2.
3.
Identified
Analysed
Evaluated (Baseline)
CCTV surveys
Inspection of existing Grease Removal Unit (GRU)
GRU maintenance procedures investigated
Staff interviews
Blockage history
Kitchen practices
Awareness
Site survey
Methodology (Continued)
FOG Hotspots
4.
5.
6.
7.
Potential solutions selected and installed.
Minimum of 6 month trial
Difficulties
Information Evening
Midleton FOG Project
System Types Tested:
No. of Installations
Passive Interceptor (Untreated)
3
Passive Interceptor(with Biological Treatment)
3
Active/Mechanical Interceptor
5
Biological Treatment System
2
Midleton FOG Project
Site Type:
Fast Food Takeaway s
Restaurants
Laundrettes
Butcher Shops
Convenience Shops
Fish Retailer & Manufacturers
Hotels
Bar/ Restaurants
Chinese Restaurants
Hospitals
Supermarkets
Pumping Stations
Sewer Hotspots
Wastewater Treatment Plants
Café Bakeries
Sandwich Shops
Quantity:
2
2
1
1
3
1
1
1
1
1
1
4
2
1
1
1
Methodology (Continued)
Trial Period
1. Monitoring
2. Observing
3. Recording
4. Maintaining
5. Sampling Programme
6. Final CCTV Survey
Active/Automatic vs. Passive
Systems
Automatic/Active vs. Passive Systems
Active
Passive
Moving Parts,
power, water
Volume
Location
Compact
Large
At Source
At or away from
source
Maintenance
Interval
Waste FOG
Waste Food
Biological Dosing
1 Day
2 Weeks (depending
on storage and load)
Clean
Dirty, Contaminated
Not decaying
Decaying
Occasionally
Portable Interceptor
Similar to passive interceptor
Maintained by contractor
Unit swapped with clean unit
every two weeks.
Full unit is removed from site
and cleaned at contractors
premises
Removes need for maintaining
unit within kitchen – hygiene
and odour issues
Aluline - BioBlock
Biological treatment for use in
sewer network
Installed in manhole at FOG
Hotspot 1
Replaced each month
Build up still occurred
Blockage rate significantly
decreased
Cleveland Biotech - Bactaerator
Biological treatment for use in
pumping stations
Water is aerated continuously
Bacteria and nutrient solutions
are dosed into water at times
of low flow
Build up of FOG on walls
decreased
Cleaning interval increased
Cleveland Biotech - Bactaerator
1 week since previous
cleaning
15 weeks since previous
cleaning
Root Cutting
Root intrusions shown in
initial survey (24/07/06)
Re-growth of roots 8 months
after cutting (31/03/08)
System Performance Summary
Lowest Highest Average
Result Result Result
(mg/l): (mg/l): (mg/l):
% < 50
mg/l:
% < 100
mg/l:
120
0
0
8896
4275.7
0
0
1148
1498
1323
0
0
1
6
5
147
73
<1
147
1977
245
147
729.3
94.6
0
0
60
0
16.7
60
8
15
799
175.4
25
50
8
38
1056
327
12.5
37.5
Site
Customers/
Meals per Day
Existing Grease
Management System
Grease Management System
Installed
No. of
samples
analysed:
Fast Food
Takeaway 1
60 (Weekday);
200 (Weekend)
200 litre JFC passive
interceptor
None
1
120
120
Restaurant 1
Up to 50 at
weekend
None
Aluline AG2 300 litre passive
interceptor with treatment.
3
191
Butcher Shop 1
150 - 500
None
2no. 21 litre PVC Fabrications
Passive Interceptors
2
Fish Retailer &
Manufacturer 1
70 approx.
None
3no. 50 litre Miskin mobile
passive interceptors
1) Shop
2) Kitchen
3) Oven
3270 litre Kent Stainless
passive interceptor with
treatment
JFC GT02 200 litre
underground passive
interceptor downstream of
existing trap
Hotel 1
up to 1200
220 litre grease trap
Convenience
Shop 2
100 to 200 from
deli
Domestic model JFC
underground passive
interceptor
Fast Food
Takeaway 2
400 to 600
None
Fatstrippa interceptor
6
20
525
212
16.7
33.3
Hospital 1
Up to 290
400 litre Blucher passive
interceptor
Service Package with
biological treatment
9
34
813
245.2
11.1
44.4
Café/Bakery 1
Not known
None
1
331
331
331
0
0
Restaurant 2
Not known
None
2
29
205
117
50
50
Sandwich Shop 1
Not known
GreaseShield Mechanical
Interceptor
4
129
982
632.3
0
0
FS05 Fatstrippa Active
Interceptor
FS10 Fatstrippa Active
Interceptor
None
System Performance Summary
Site
Average % < 50 mg/l: % < 100
Result
mg/l:
(mg/l):
Existing Grease
Management System
Grease Management System
Installed
Fast Food Takeaway 1
200 litre JFC passive
interceptor
None
120
0
0
Restaurant 1
None
Aluline AG2 300 litre passive
interceptor with treatment.
4275.7
0
0
Butcher Shop 1
None
2no. 21 litre PVC Fabrications
Passive Interceptors
1323
0
0
None
3no. 50 litre Miskin mobile passive
interceptors
147
729.3
94.6
0
0
60
0
16.7
60
175.4
25
50
327
12.5
37.5
Fish Retailer &
Manufacturer 1
1) Shop
2) Kitchen
3) Oven
Hotel 1
220 litre grease trap
Convenience Shop 2
Domestic model JFC
underground passive
Interceptor
3270 litre Kent Stainless passive
interceptor with treatment
JFC GT02 200 litre underground
passive interceptor downstream of
existing trap
Fast Food Takeaway 2
None
Fatstrippa interceptor
212
16.7
33.3
Hospital 1
400 litre Blucher passive
Interceptor
Service Package with biological
treatment
245.2
11.1
44.4
Café/Bakery 1
None
FS05 Fatstrippa Active Interceptor
331
0
0
Restaurant 2
None
FS10 Fatstrippa Active Interceptor
117
50
50
Sandwich Shop 1
GreaseShield Mechanical
Interceptor
None
632.3
0
0
Comparison of systems
Design
Conformity to I.S. EN 1825 Standards
User Satisfaction
Reliability
Maintenance - User Friendliness
Ease of access
Hygiene
Odours
Maintenance interval
Contractor or in-house cleaning
Waste
Comparison of systems
Performance
Effluent sample analysis
CCTV surveys (before and after)
Blockage History (before and after)
Level of Confidence
Cost
To purchase
To install
To maintain
Outputs of Midleton Case Study
Statistics were compiled regarding the waste being
removed from the systems
Better understanding of systems on the market in
Ireland
Supplier/manufacturer procedures observed
Compliance with I.S. EN 1825 standards
Results of sample analysis
Outputs of Midleton Case Study
Maintenance procedures observed and rated
Contractor behaviour observed
Greater appreciation of all points of view
User
Supplier
Contractor
Outputs of Midleton Case Study
Greater understanding of kitchen practices
Where most FOG is generated in different types of FSE
Wok cooker, combination oven etc.
Tools for handling FOG related issues
Ireland specific FOG letters
Grease Trap Guidance sheets
Kitchen Practice Guidance sheets
Grease Trap Maintenance Record sheets
Observations - Licensing
Applications
Site inspections
Co-operation
Planning Department
Environmental Department
Environmental Health Officers
Guidance not available.
Confusion caused by application form and
process.
Resources
Observations - Licensing
Enforcement & Monitoring
Site inspections required
Co-operation
Records
Kitchen practices
Maintenance practices
Disposal
Blockages
Resources
Method based consent
Observations - Disposal of waste
Cost
Traceability
Large quantities vs. Small quantities
Facilities
Clarity
Lack of disposal records for waste FOG
(both by contractors and business owners).
Contractors must be monitored
Observations - GRUs
Specification
Sizing
Operation & Maintenance
IS EN 1825
Installation
Incorrectly installed or situated traps.
Appliances passing through grease trap.
Observations - GRUs
Maintenance
Traps maintained incorrectly or not at all.
Lack of knowledge of existence of GRU (Grease
Removal Unit).
Forgery of grease trap maintenance records by
staff to avoid doing the work.
Poor kitchen practices negating grease trap
maintenance.
Conclusions
Disposal of grease trap waste is a significant issue
Waste stream is dramatically increasing
Removal at source is most economical solution
Enforcement is necessary
Maintenance is vital
Education & Awareness
Conclusions (continued)
No one system is suitable for all sites
Challenge
Cost – Benefit
Cork County Council Report
WRc Reports
MEng Sc Thesis: “Recovery of Waste FOG for use as
a Biofuel in Ireland”
Acknowledgments
Noel O’Keeffe
- County Engineer, Cork Co. Co.
Matt Shortt
- WSNTG
Tadgh O’Connor
-DEHLG
Shane Kennedy
-Cork Co. Co.
WRc
Midleton Town Council
Cork Co. Co. Environmental Section