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

Verbal Description

Survey #13 - Post  Zimpro shutdown

The community odor survey was conducted on the early afternoon of Wednesday, March 13, 2002. It was a sunny day with shifting winds at 3-4 mph generally out of the southwest or west. The temperature was about 60°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 non-detectable to very faint and the hydrogen sulfide (H2S) concentrations ranged from 0-6 parts per billion (ppb). A faint sludge odor was detected at station #5 which was directly downwind of the MFWTP today.

Non-detectable to faint odors were detected at the three (3) sampling stations (#6-#8) in the neighborhoods east and southeast of the plant. A very faint MFWTP sludge odor was detected at station #6 but a noticeable industrial chemical odor was detected at station #7. H2S levels were 7-8 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 industrial chemical odor level was very faint at station #11 and a noticeable industrial chemical odor was detected at station #10. The H2S concentrations were 4-5 ppb.

At the MFWTP, there were moderate winds generally at 2-4 mph out of the south southwest but shifted in various locations at the plant. The odor intensity at the seven (7) sampling stations around the plant ranged from faint to noticeable. H2S concentrations at these stations ranged from 3-25 ppb with the highest readings measured at station #12 where the average H2S was about 13 ppb, where the wind had shifted from the treatment plant. Most of the odors detected today were activated sludge or processed sludge. Both biotowers were in service and both scrubbers were in operation. The new stationary incinerator (PTO) appeared to be operating normally. Zimpro was out of service. The plant is currently dewatering sludge, mixing it with sawdust if necessary and hauling to the landfill. The new dryers and RTO's are not in service yet.

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