Molalla to hold second-quarter compliance meeting
The City of Molalla will hold a second-quarter compliance meeting regarding the wastewater treatment plant on June 5 at noon in the conference room at City Hall. The meeting is open to the public and residents interested in operation of the city's wastewater system are welcome.
It comes with Holly DeRamus's Compliance Specialist Report for March 26 to May 15. She is a 35-year veteran of the wastewater field with other experience including visiting more than 100 wastewater treatment plants, 25 of which were lagoon plants in Oregon. She's developed a training manual for lagoons and delivered workshops for operators around the world.
"Lagoon systems are completely unique as they are dependent on nature to assist in the conversion of organic material (sewage) into clear water and biosolids (sludge)," she said in her second-quarter report. "The original lagoon system in Molalla…relied completely on nature or algae to supply the needed oxygen to facilitate the conversion. This is tough. Algae doesn't thrive in the winter, the rain adds to the challenge and a lagoon system is not designed nor will it meet a high-quality effluent requirement. Molalla has a DAF system that was designed to remove the excess algae from the effluent."
During this quarter DeRamus noted a number of items were addressed. On April 2, the city retained her as an outside compliance specialist to track its compliance with the consent decree.
The city evaluated and prepared a report on whether the installation of floating mixers or duckweed in the lagoons would be a cost-effective method for improvement treatment at the current wastewater treatment plant. That contract was executed on May 7. Both of the above actions were taken within 90 days of the consent decree.
Within 60 days of the consent decree filing, the city provided notice of results of the 2017 lagoon leak test, along with a link to the final report and summary of work to be completed under the Master Plan.
This was sent to all registered well owners within one quarter mile of the wastewater treatment plant lagoons. Letters were sent to property owners by mail on May 10 and the notice published in the Molalla Pioneer May 15.
Complying with the Reclaimed Water Use Plan, the city monitored to determine if water is meeting Class A standards regardless of the class specified in the RWUP. Monitoring is underway.
A meeting was held on April 25 with all irrigators and their staffs training them to comply with the RWUP and specific issues of concern including potential for overspray, setback compliance and prevention of ponding and evaluation of run-off potential. The city also supervised and instructed irrigators and their staffs to ensure the placement and use of all hand-line sprinklers used for irrigation with city recycled water on the North Coleman Ranch property complies with the RWUP.
Within 90 days of entry into the amended consent decree the city asked Coleman Ranch owners for permission to install visible markers at the ranch marking setbacks and buffer zones required by RWUP. If permission is granted the city will work with Coleman Ranch to install such markers. That request was sent on May 13.
The city will maintain a 24-hour voicemail and email hotline for reporting RWUP violations. It also will keep a record of all reports made to the hotline and email account on the city's website and email and available to the public.
DeRamus's report notes the treatment plant performed well during the period. However, she does note a few violations, all at the end of April. A major rainstorm impacted the plant for about 10 days. The highest flow rate was over 3.5 million gallons per day, or three times the normal plan flow pattern, because of the water produced; and flows remained high at over 1.5 MGD for the next few days.
Lagoon systems rely on natural weather influences like the sun as well as hydraulic influences. They need time to treat wastewater, DeRamus said in her report. Too much flow doesn't give the lagoons time for the biology to work and do a complete conversion of the organic material. However, Molalla's plant didn't discharge any untreated wastewater. Nearby cities of Portland, Salem and Woodburn also experienced combined sewer overflows during the April storm.
"Moving forward, I would like to say that the city of Molalla has taken up the challenge to get things corrected and move forward in a positive well-planned way," said DeRamus in her report. She also noted there is a coordinated effort to comply and excel at the challenges the city faces. "The volume of data and reporting reviewed is not being replicated anywhere else for a city this size and staff should be commended for their efforts thus far," she concluded in her report.