HomeMy WebLinkAbout06.a.1) (Handout) Update on Field Verification of Primary Sedimentation Basin Baffles.Item No. 6.a.1)
Field Verification - Primary
Sedimentation Basin Baffles
Samantha Engelage, P.E.
Assistant Engineer
Treatment Plant Planning
August 15, 2013
1"�. Central Contra Costa Sanitary District
Nutrient Facility Plan
& Site Characterization
Element 1. 1111 Element 2:
Plant Optimization Nutrient Visioning Plan
(near term w /existing facilities) (long term w /new facilities)
Primary Baffle Study
Total Nitrification Study
(2010 HDR)
BioWin Configuration
Plant Optimization for II I Evaluation
Ammonia Removal
II Nitrification Rate Tests II
IVvanide Removal Ontionsll
6. a. /)
�Nanddar�
Element 3:
Site Characterization
(contaminated soil dispos:Vtrestment
for new facilities)
1
Studv Background
• Low primary sedimentation basin (PSB)
performance when compared to
literature
Average TSS Removal (Metcalf & Eddy, 1991)
50% 70%
verage BOD Removal (Metcalf & Eddy, 1991)
25% 40 %,�
HDR Modelinq Results
• 16% Improved
TSS Removal
• Payback -2 yrs
for aeration
savings
• Payback -9 yrs
with seismic
reinforcements
MEW
2
Baffle Field Verification
• Objectives -
- Impact on TSS & BOD
removal
— Aeration savings in the
2° process
• Water Quality (WQ)
Sampling
• Sludge Depth &
Removal
PSB Schematic with Baffles
-254'
-3811
a
4
3
2
1
Primary Effluent Primary Sedimentation Basin Distribution Pre - Aeration
Effluent Launders Channel Tanks
Channel
WQ Sampling - After Install
`removals calculated based on concentrations
• Baffled basin trending with better performance
• High variability
• No statistical significance
45
=40
A
35
30
'0 25
d 20
z
0,15
v
_2 10
fn
Of 5
n
0
a
Baffles significantly increased sludge removal by 19%
(mass basis)
• Statistically significant at 95% confidence interval
Sludge Removal Rates
M
Grab Samples
Composite Samples
(July — August 2012)
(November 2012 — January 2013)
Unbaffled
Baffled
p- Statistic
Unbaff led
Baffled
p- Statistic
Removal ( %)'
Basin
Basin
(a = 0.05)
Basin
Basin
(a = 0.05)
(n = 10)
(n = 10)
(n = 10)
(n = 10)
TSS
45 f 13
53 t 20
0.14
77 f 13
80 t 6
0.56
BOD
33 t 17
32 t 15
0.45
49 f 27
56 t 16
0.48
BODp
NA
NA
NA
59 f 28
67 t 11
1 0.41
`removals calculated based on concentrations
• Baffled basin trending with better performance
• High variability
• No statistical significance
45
=40
A
35
30
'0 25
d 20
z
0,15
v
_2 10
fn
Of 5
n
0
a
Baffles significantly increased sludge removal by 19%
(mass basis)
• Statistically significant at 95% confidence interval
Sludge Removal Rates
M
Field Verification Summary
• Water Quality Sampling
— No significant differences detected
• Small dataset
• Difficulties in tank isolation & representative samples
• Sludge Depth & Removal Data
— Significantly increased solids removal by 19%
• Mirrored trends in water quality data
• Projected 10% lower BOD load to 20 aeration process
• Operational Cost Savings
— 8% natural gas reduction = $150,000 /year savings
— Maintenance $1,000 /year
• Simple payback = 4.3 years
•t
Next Steps
• TP Planning recommends the baffle system be
installed in the other 3 basins
• Capital to include installation in the Primary
Treatment Renovation Project, DP 7285
a�R R � a a •
Now NNW Ali
a • 4 �
R R R
5
Questions?