MERC ER01-14
10
AUG Live Organisms
≥
10 - <50 µm
Samples from the time-integrated chambers.
Sample ID
Ave (#/ml)
SD
Challenge
1,260
62
Treated
947
161
Phytoplankton Observations
Challenge and Treated
The majority of cells in both challenge and treated samples were 15 -25 µm with nothing
measuring greater than 30 µm. The dominant species in both the challenge and treated samples
was
Chaetoceros
(small chains - none longer than 3 cells).
AUG Active Chlorophyll-a Data
Challenge and treated samples from the time-integrated chambers. Ambient sample was taken
before augmentation.
7. FXIT-20
7.1. FXIT-20-COMM
Prior to any formal testing, a mechanical commissioning run of the Filtrex system using a
20-µm filtration mesh size was provided to assure appropriate treatment operations. This run
was used to identify and correct initial mechanical or operating issues. During the
commissioning process the feed pump capacity was adjusted to 250 m
3
/hr, the outlet throttling
valve was adjusted, the back wash delta pressure set point was established, and instantaneous and
accumulated data logging was set up. Data collected during commissioning was only used for
test preparations and is not provided in the final report.
After treatment system commissioning was completed and accepted by Filtrex, MERC
conducted two trials to evaluate the 20-µm filtration mesh size for biological efficacy. The
biological efficacy trials focused exclusively on live organisms ≥ 50
µ
m and ≥10 - <50 µm in
size. Each test was conducted using the MERC barge piping system set in the sea-to-sea
configuration. The two tests included one trial of filter efficacy with natural Baltimore Harbor
water (FXIT-20-NTL) and a second trial with augmented natural water to increase TSS and POC
(FXIT-20-AUG). Filtrex selected a flow rate of 250 m
3
/hr and 1.2 bar of backpressure be
provided to the Filtrex filter system.
Sample ID Ave (µg/L)
SD
Ambient
16.44
0.29
Challenge
13.84
0.13
Treated
13.03
1.14
