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Officials debate costs for a interim fix
3/30/2007 By: Carole McWilliams
Bayfield Sanitation District board members debated options last week on ways to keep the Bayfield sewage plant in compliance with state permit limits for the next year and a half, while a new plant is built.
Engineer Greg Woodward described the options – most of them expensive.
Removing sludge from the second and third lagoons will cost $100,000 to $110,000. The sewer board has already committed to do that.
Installing a second baffle and addition of a chemical polymer in the third lagoon could improve settling out of treated sewage before it is discharged into the river. The cost estimate for that is $54,000, according to sewer board chairman Ed Morlan. The board committed to that last week.
Anaerobic pre-treatment reduces organic loading of sewage as it comes into the first lagoon. The plant’s most vexing permit violation has been excess organic loading coming in.
In optimum conditions, this can reduce organic loading 40 to 50 percent, Woodward said. In the Bayfield plant, the reduction could be 20 percent, he said. It will take four to six months to get it cranked up and operating if all goes well, and six to nine months if it doesn’t, he said.
Morlan listed the cost at $68,000, or $138,000 if this compartment is covered to keep down potentially strong odors.
Sewer board member Brad Elder objected to the time it takes to get this working, and that it apparently wouldn’t get a state permit revision to recognize more plant capacity.
Morlan responded, “We’re still trying to get the plant into compliance at the current level.”
Town and sewer district manager Justin Clifton added, “Nobody from the state has given us any indication that they want us to seek permitting for additional capacity. They want assurance of compliance, and they will consider lifting restrictions (on issuing new sewer taps). A request for more capacity won’t be well received.”
The board balked at approving the anaerobic pre-treatment cell, apparently because of the long time lag to know whether it was working to reduce organic loading.
The next lagoon improvement option is the most expensive short of installing package treatment units for around $500,000. A sand filtration bed would be installed at the end of the process to further clean effluent before it goes into the river. It would cost around $315,000, Morlan said.
During the March 19 discussion, board members indicated they considered that a last option.
But Southern Ute Tribal Utilities representative Jerry Thomas advised at the March 21 meeting, “The package plants can take a portion of your loading, but they don’t insure the quality of your effluent. The sand filtration would be good assurance of quality effluent. We got the feeling that’s the kind of assurance the tribe is looking for.”
The tribe gets its drinking water out of the river just over a mile below where the Bayfield sewage plant discharges. It was instrumental in pressing the state to issue a cease and desist order and building permit moratorium on the district and town one year ago.
The rest of the discussion on March 21 was on different types of package plants. Town staffer Joe Stewart, who helps operate the plant, objected that they need 3-phase power, and that connection is a mile away. The current 3-phase conversion system eats pumps, he said.
“There’s not enough power to make the aerators work,” Stewart continued. “You run them all at one time and it will pop a breaker.”
Woodward described sequencing batch reactor (sbr), fixed film, and membrane bio-reactor (mbr) package plants. The mbr is the system the board chose for the new plant.
He advised that mbr systems like consistent loading, not the erratic spikes that have plagued the Bayfield system.
Plant operator Ron Saba warned the package plant will need more employees to operate it.
Woodward said, “The cost of a package plant is high relative to the value you will get, unless you can re-sell it (when the new plant is done).” The other steps, referred to as “hot-rodding” the lagoons, will give more benefit for the cost, he said.
He also questioned the technical logistics and cost of getting a package plant into place at the lagoons, and again when it is removed.
Clifton asked, “What is the most stable and cost effective way to spend a half million dollars? It seems like the package plant has a lot more unknown variables.”
After a couple motions made and then withdrawn by sewer board members, Clifton said, “I’d support the package plant if I heard any real enthusiasm from the engineers, on any of them. At this point, I’d support a commitment to the state to do this (lagoon hot-rodding) or this (package plant).”
Board member Mike Hoban re-stated that, “Among the learned people, there’s no enthusiasm for the package plant, and for all the unlearned people, it’s the silver bullet.”
The board finally approved Elder’s motion “to direct staff to prepare an action plan that includes package plants or the sand filter and anaerobic, without a cover.”
Either way the cost will be around $400,000, district attorney Bud Smith said.
In other action, the board set a public hearing for April 25 on the bonds the district will issue to pay for a new sewage treatment plant. It’s estimated to cost $6.5 to $7 million. The district has just over $1 million on hand, plus a $1 million state grant. The rest will be a low-interest loan from the Colorado Water and Power Authority.
Bud Smith said the hearing will include a presentation on the type of treatment system that was chosen and why. He assured that revenue from Gem Village customers won’t be used for this.
If Gem Village sewage is eventually piped over the hill to the new plant, instead of upgrading or replacing the Gem Village plant, those customers will pay for the lift station, Smith said.