Mountain Top Facility Meets Standards With Compact Wastewater Treatment System
About the author:
Bill Hensley is the international projects manager for Orenco, where he provides design, installation, and operational training and support for the company’s wastewater collection and treatment solutions. He is based in Oregon, USA, and can be reached at [email protected]. Jennifer Wimber is a senior writer at Orenco and is based in Utah, USA. She can be reached at [email protected].
Bill Hensley & Jennifer Wimber
undefinedAn overnight conference and recreation center located in the mountains had several onsite wastewater treatment units that were not meeting treatment level requirements.
The project engineer recommended the failing units be replaced with an Orenco AdvanTex Wastewater Treatment System, due to its small footprint, transportability, and track record for reliably meeting or exceeding required treatment standards.
Crusaders Galston Gorge Conference & Recreation Centre
The Crusaders’ (CRU) Galston Gorge Conference and Recreation Centre hosts up to 220 people at a time for various overnight events throughout the warmer months of the year. Its popular facilities include twelve lodges, seven meeting and conference rooms, a gym, a dining hall, and several outdoor activity sites. Unfortunately, its onsite wastewater treatment units were not able to meet the required treatment levels and needed to be replaced.
The Centre hired an environmental engineering firm to evaluate and present the options. Although a sand filter would be able to meet the treatment requirements, it would take up too much space. The same was true of an activated-sludge treatment system when taking into account flow-balance tankage requirements. A membrane bioreactor system would also be able to meet the treatment standards, but the cost would be too high.
Handling Seasonal Wastewater Flows
Wastewater flows at Galston Gorge come primarily from staff housing, guest cabins, toilet and shower blocks, and kitchen and laundry facilities. Because of the seasonal nature of the business, the flows are highly variable. The new wastewater treatment system would need to produce consistently high-quality filtrate despite these sporadic flows, as well as accommodate very shallow soils at the site.
After considering all options, project engineer Jasmine Kable recommended a packed-bed filter system. In particular, she recognized that an Orenco AdvanTex Treatment System was best suited for this project, due to the size constraints, the difficult mountaintop location, and the required treatment levels. The technology was expected to effectively manage nitrification and denitrification. It could also meet strict organic and suspended solids limits, even during peak flow conditions.
How the AdvanTex Treatment System Works
AdvanTex treatment systems use a fixed-film, attached-growth treatment process and are an excellent solution for treating sanitary wastewater. In this system, wastewater is uniformly distributed onto the textile media in an unsaturated condition. The system uses fractional-horsepower fans to draw air through the media and provide sufficient oxygen for aerobic digestion. Low-horsepower, high-head turbine pumps operate intermittently with sophisticated controls that automatically adjust recirculation ratios and pump run-times based on daily flows.
Treatment System Installation at Glaston Gorge
Kable consulted with the Galston Gorge site director and then collaborated with Innoflow Wastewater Specialists, an Orenco dealer, on the final treatment system design. Innoflow was able to repurpose 9,775 gallons of tankage from the failed wastewater treatment systems at Galston Gorge by converting them into septic tanks and installing effluent pumping units in the tanks to transport partially treated wastewater to the new treatment facility.
The facility includes 17,830 gallons of additional primary treatment tankage, which maximizes overall performance while allowing for a smaller, less expensive secondary treatment system consisting of four AdvanTex AX100 units. Surge control tankage of 7,925 gallons ensures a consistent daily flow to the units.
Grease tankage of 1,585 gallons and pre-anoxic tankage of 6,075 gallons were also included in the design. A drip irrigation system with a Wisconsin mound provides final polishing of the treated effluent.
Because of the very shallow soil, extended periods of wet weather sometimes cause saturated ground conditions, making the dispersal field unusable. When this happens, treated wastewater is held in storage tankage of 86,540 gallons until the weather dries up enough that effluent can again be dispersed into the field.
Wastewater Treatment System Operations & Maintenance
In addition to working with Innoflow on the design and installation of the new treatment facility, the Galston Gorge center also contracted with S3 Ltd., a subsidiary of Innoflow, for operation and maintenance. After the first year, routine maintenance visits will likely occur every 3 to 6 months. They include tasks like checking the operation of pump and float switches, cleaning filter cartridges, and flushing the lateral pipes in the units. Scum and sludge accumulation in the septic tanks is typically measured once a year, with the tanks being pumped out as needed.
Monitoring & Alarms
An Orenco TCOM telemetry control panel allows for 24/7 remote monitoring of the treatment system. If an alarm condition occurs, the control panel will send an email notification to the service provider immediately. This allows the operator to monitor the system with their smart phone and/or computer. The TCOM panel maintains logs for system conditions and events, including pump run-time, pump cycles, and alarm conditions. These logs are downloadable as spreadsheets or word processing documents.
Located at the top of a mountain, with steep banks all around and limited space available for a new wastewater treatment system, the Galston Gorge Centre presented quite a challenge for designers. Fortunately, AdvanTex treatment technology is well suited for such sites and consistently meets the strict nutrient limits they often require.
Additional Project Details & Parameters
Designers
|
Design Parameters
|
Installer
|
Raw Influent
|
Service Provider
|
Treatment Requirements
|
Installation Date
|
Effluent Quality*
|
Primary Treatment
* Sample collected on 10 March 2021 and analyzed by a third party |
Collection System
|
Secondary Treatment
|
Monitoring and Control
|
Tertiary Treatment
|
Dispersal**
** The dispersal field isn’t used during saturated ground conditions, so a large volume of storage tankage is required during extended wet weather. |