MONROE - Efforts to combat the smell coming from the city Wastewater Treatment Plant have culminated in a plan presented to the Monroe Common Council Tuesday that experts said has a success rate of nearly 100 percent.
Utilities Supervisor Mike Kennison said staff have been working with architect and engineer company McMahon Associates Inc., based in Machesney Park, Illinois, since the firm was hired in July to identify the cause of the intermittent odor problem plaguing the city. Samplings were taken from the plant's equalization tank and tested in California, McMahon Senior Vice President Timothy Bronn told aldermen Tuesday.
"Our big culprit down there is hydrogen sulfide, which is a common gas in that type of plant," Bronn said. "There are very well-established technologies to deal with it."
Kennison explained the cause for the smell was the result of a constantly running equalization tank, implemented in the recent $25 million project to create a modern treatment plant for the city.
Bronn presented three possible solutions to the council. Following tours of facilities in Kaukauna, Neenah and Germantown, Kennison and other city staff agreed with Bronn that a biofilter methodology would be the best option for the Monroe plant.
The project to improve wastewater operations has been fraught with issues between the city and the plant's designer, AECom. In March 2015, Minneapolis-based law firm Hammagren & Meyer was hired to oversee the project. A current lawsuit between the city and AECom includes a complaint about two digesters at the plant, which never ran at the temperature required to process waste, and will include the smell issues, Kennison noted.
"They should have known we would have the smell," Kennison said at the meeting.
He added that the cost now needed to install a biofilter system would have likely been necessary if it had been done alongside the other work on the plant. However, he said it would have been at a lower cost because of design requirements and would have been previously resolved.
The cost of the biofilter was outlined in a planning report submitted by Bronn to the city dated Nov. 15, which included initial project costs as well as the expense of 20-year maintenance on the systems. All three options to mitigate the odor problem caused by the sulfur compounds require oxidization.
A reactive media filtration plan would consist of a vessel filled with chemicals meant to convert sulfur into biodegradable sulfides. The cost of this plan would include an original expense, referred to as capital cost, of $330,000 and $467,500 in maintenance costs, resulting in a total of more than $797,500 to implement.
The second option, photoionization, would oxidize the noxious element through the use of ultraviolet light. Bronn's report noted this method "is very effective for odor spikes" as well. The cost of photoionization would be an initial investment of over $446,000 for equipment, ductwork, dome modifications and other work at the site, in addition to $493,000 in 20-year expenses.
A biofilter system utilizes the growth of bacteria on natural components, in Monroe's case, shredded tree roots. The bacteria use sulfur as an energy source in the oxidization, nullifying the odor. Though Bronn noted the upfront capital expense of nearly $488,000 is the most expensive option initially, but the maintenance costs are the lowest at $194,000, making it roughly $115,000 less costly than the other two options.
By general consensus, council members advised staff to move forward with the biofilter plan. Alderwoman Brooke Bauman expressed frustration the issue had not been dealt with during the multi-million-dollar project at the treatment plant.
Bronn informed the city that a Department of Natural Resources loan program for small projects, those at a cost of under $2 million, would likely be awarded to Monroe if the city applied. Because the annual application deadline passed on Oct. 31, Kennison said costs for the work could be taken from capital funds with the utilities department and reimbursed through the loan later.
Utilities Supervisor Mike Kennison said staff have been working with architect and engineer company McMahon Associates Inc., based in Machesney Park, Illinois, since the firm was hired in July to identify the cause of the intermittent odor problem plaguing the city. Samplings were taken from the plant's equalization tank and tested in California, McMahon Senior Vice President Timothy Bronn told aldermen Tuesday.
"Our big culprit down there is hydrogen sulfide, which is a common gas in that type of plant," Bronn said. "There are very well-established technologies to deal with it."
Kennison explained the cause for the smell was the result of a constantly running equalization tank, implemented in the recent $25 million project to create a modern treatment plant for the city.
Bronn presented three possible solutions to the council. Following tours of facilities in Kaukauna, Neenah and Germantown, Kennison and other city staff agreed with Bronn that a biofilter methodology would be the best option for the Monroe plant.
The project to improve wastewater operations has been fraught with issues between the city and the plant's designer, AECom. In March 2015, Minneapolis-based law firm Hammagren & Meyer was hired to oversee the project. A current lawsuit between the city and AECom includes a complaint about two digesters at the plant, which never ran at the temperature required to process waste, and will include the smell issues, Kennison noted.
"They should have known we would have the smell," Kennison said at the meeting.
He added that the cost now needed to install a biofilter system would have likely been necessary if it had been done alongside the other work on the plant. However, he said it would have been at a lower cost because of design requirements and would have been previously resolved.
The cost of the biofilter was outlined in a planning report submitted by Bronn to the city dated Nov. 15, which included initial project costs as well as the expense of 20-year maintenance on the systems. All three options to mitigate the odor problem caused by the sulfur compounds require oxidization.
A reactive media filtration plan would consist of a vessel filled with chemicals meant to convert sulfur into biodegradable sulfides. The cost of this plan would include an original expense, referred to as capital cost, of $330,000 and $467,500 in maintenance costs, resulting in a total of more than $797,500 to implement.
The second option, photoionization, would oxidize the noxious element through the use of ultraviolet light. Bronn's report noted this method "is very effective for odor spikes" as well. The cost of photoionization would be an initial investment of over $446,000 for equipment, ductwork, dome modifications and other work at the site, in addition to $493,000 in 20-year expenses.
A biofilter system utilizes the growth of bacteria on natural components, in Monroe's case, shredded tree roots. The bacteria use sulfur as an energy source in the oxidization, nullifying the odor. Though Bronn noted the upfront capital expense of nearly $488,000 is the most expensive option initially, but the maintenance costs are the lowest at $194,000, making it roughly $115,000 less costly than the other two options.
By general consensus, council members advised staff to move forward with the biofilter plan. Alderwoman Brooke Bauman expressed frustration the issue had not been dealt with during the multi-million-dollar project at the treatment plant.
Bronn informed the city that a Department of Natural Resources loan program for small projects, those at a cost of under $2 million, would likely be awarded to Monroe if the city applied. Because the annual application deadline passed on Oct. 31, Kennison said costs for the work could be taken from capital funds with the utilities department and reimbursed through the loan later.