Morris Forman Wastewater Treatment Plant
Community Odor Survey Project
(WEA Project #266-04)

Verbal Description

Survey #7 - Post  Zimpro shutdown

The community odor survey was conducted on the afternoon of Tuesday, December 4, 2001. It was a sunny day with light winds at 2-8 mph generally out of the south. The temperature was about 68°F.

For the five (5) ambient sampling locations (#1-#5) in the neighborhoods north and northeast of the treatment plant, along the Dumesnil St. corridor, the odor intensities were very faint and the hydrogen sulfide (H2S) concentrations ranged from 4-7 parts per billion (ppb). A very slight sludge odor from the MFWTP was detected at station #2.

Non-detectable to very faint odors were detected at the three (3) sampling stations (#6-#8) in the neighborhoods east and southeast of the plant. No MFWTP odors were detected but a detergent odor was detected at stations #7 and #8. H2S levels were 6-10 ppb at these stations.

For the three (3) sampling stations (#9-#11) located south and southwest of the treatment plant in the more industrial areas of the City, the odor levels were very faint at stations #9 and #11 but a noticeable industrial chemical odor was detected at station #10. The H2S concentrations were 5-7 ppb.

At the MFWTP, there were light winds at 2-6 mph out of the south. The odor intensity at the seven (7) sampling stations around the plant ranged from faint to strong. H2S concentrations at these stations ranged from 4-13 ppb with the highest readings measured at station #15 where the average H2S was about 13 ppb. Both biotowers were in service but scrubber "A" was out of service. The portable incinerator was on standby operating mode today. The existing stationary incinerator (PTO) appeared to be operating normally. Zimpro was taken out of service, perhaps temporarily, on December 3, 2001. The decant tanks still held Zimpro sludge. On-site odors were significantly improved during this survey with the Zimpro system off-line.

Odor surveys will be conducted an average of once every two weeks during this project and will be conducted through August, 2002.