Meridian School District, Washington

Enhanced nitrogen removal for high groundwater

The Meridian School Districtin Bellingham, Washington, needed to build a new elementary school for 600 students. Because of high groundwater and strict nutrient limits, the school was required to install a wastewater system that could meet a TN requirement of 20 mg/L despite an extremely high level of influent ammonia, which is common with schools. The district’s engineer contacted FexTex Systems, an Orenco distributor, who suggested four of Orenco’s AdvanTex AXMax textile filter units to provide 2-stage secondary treatment, as well as tertiary treatment (BOD polishing) behind an upflow filter (for enhanced nitrogen-removal). The design also included alkalinity and carbon feed systems and a recirc return line. This robust and sophisticated solution was designed to meet not just current nutrient reduction requirements but future requirements, as well. For the present, FexTex and Orenco have been commissioning the various processes and stages, followed by sampling, to find the optimal balance of treatment and cost. The new school — Irene Reither Elementary — opened in January 2014 and has posted TN levels under 10 mg/L.* The entire system is monitored by an Orenco TCOM remote telemetry control panel, which automatically tracks daily flows and conditions. “We’re seeing increasingly stringent nitrogen limits, everywhere,” says Orenco engineer David Lepre. “This project shows that we can install a system that meets these new nitrogen limits, even in the most difficult of situations.”

* Samples collected and analyzed by a third party between 3-25-14 and 12-10-14.

Wapsie Valley High School, Iowa

Excellent treatment despite variable flows

Wapsie Valley High Schoolhad surfacing wastewater flowing over the school’s parking lot from a failed, 45-year-old drainfield. Wildly varying flows and site constraints posed additional problems. During the school year, wastewater flows averaged 5,000 gpd (18.9 m3/day), and big events strained the system’s capacity to a peak of 13,000 gpd (49.2 m3/day). During the summer, however, flows dwindled to almost nothing. Most wastewater treatment technologies perform poorly under these conditions. After evaluating the situation, the project engineer, Cary J. Solberg, P.E., chose an AdvanTex Treatment System manufactured by Orenco for its ability to handle variable flows, as well as for its relatively low energy consumption and ease of installation/operation. Once the AdvanTex system was installed, the consistently high quality of the effluent took the strain off the existing drainfield, which was rehabilitated and placed back into service. Sampling showed that the system’s effluent BOD5, TSS, and NH3-N were averaging less than 10 mg/L, 10 mg/L, and 5 mg/L, respectively.*

* Samples collected between 1-13-06 and 5-10-06.

St. Francis de Sales Church, Virginia

Excellent treatment for clay soils

The Catholic Diocese of Arlington, Virginia, needed a wastewater system for a new church. The parishioners of St. Francis de Sales Churchin Purcellville had outgrown their current facility and were building a new one right next to the old one. The diocese staff approached engineer Ray Freeland, P.E., who had consulted with them on another project using Orenco’s AdvanTex Treatment Systems. The church is sited on heavy clay soils and the system needed to provide excellent treatment to preserve its drainfield and meet a permit limit of 10 mg/L BOD. Consequently, Freeland recommended a 21’ AdvanTex AX-Max unit. The AX-Max uses a multi-pass, packed-bed filter treatment technology to treat water to better than secondary standards. After treatment, the resulting effluent is dispersed via a shallow-placed drip field. The system was installed in late 2014.

Andrada Polytechnic and Patano High School, Arizona

Speedy installation for high-profile schools

Andrada Polytechnic,a 600-student school that includes academies in health sciences and transportation, shares its campus with Patano High, an award-winning 200-student alternative school. This facility needed a shared wastewater system that met requirements for energy efficiency and LEED certification. IWS, a design/build company, worked with the construction company to meet the site’s unique design considerations and threemonth timeframe. The campus installed a primary treatment system followed by eight AdvanTex AX100 secondary treatment units. Effluent is reused for subsurface irrigation.