Murfee Engineering Company’s water and wastewater infrastructure clients include public utility agencies, municipalities, river authorities, water control and improvement districts, private developers, and investor owned utilities. MEC currently represents nineteen utility districts. MEC engineers have prepared numerous municipal and special district tax and revenue bond applications to support this financing. As a result MEC design engineers are familiar with the Texas Commission on Environmental Quality’s (TCEQ) requirements for bidding and constructing municipal bond financed projects.
MEC maintains a utility planning and design team which consists of six professional engineers. These engineers are supported by two engineers-in-training and five design techs. The firm also employs additional professional engineers specializing primarily in road design, subdivisions, hydrology and water quality who often support the utility design team with site planning and drainage when necessary.
MEC maintains a close working relationship with other consultants for support services in other disciplines not specifically provided by MEC. These include treatment specialists, electrical engineers, structural engineers, geotechnical engineers and surveyors.
The project extended the LCRA’s Bee Cave water system out Hamilton Pool Road to serve developing areas. It included a 2 MGD potable water pump station constructed at an existing ground storage reservoir site off Hwy 71, over 18,000 linear feet of 16-inch potable waterline generally following Hamilton Pool Road to the West, a 250,000 gallon ground storage reservoir, a 2 MGD hydro-pneumatic water system at the end of the 16-inch waterline, and subsidiary projects that extended 12-inch waterlines to the south and to the west from the end of the 16-inch line. The project was let in three separate bids with additional line work change added to the original bids. The project included extensive coordination with outside environmental consultants as well as the representative for an individual conservation property that was being crossed. Special conditions were developed for restoration in environmentally sensitive areas and the design was, in numerous areas, augmented to respond to environmental concerns.
This is a cost reimbursement project between the City of Austin and Wild Horse Investments that consisted of approximately 8000 feet of 24-inch potable water line. The waterline tied to a City main north of US 290 at Decker Lane, crossed US 290 and then paralleled Decker Lane to Lindell Lane where it headed cross-country to the east. The line in the area of US 290 was designed and built in stages to accommodate the TxDOT US 290/SH 130 intersection construction and included bores for crossing beneath Decker Lane and under Capital Metro railroad. The project was bid as a City of Austin project and, upon completion, was accepted and is owned by the City of Austin.
This project is approximately 11,500 feet long and set generally along Webberville Road and Dunlap Road in eastern Travis County. The line connects the Hornsby Bend water wells near Webberville Road and Decker Lake Road to its elevated reservoir east of the Hornsby Bend development. The line crosses Decker Creek and Webberville Road and is generally set within easements.
Project included approximately 60,000 linear feet of wastewater interceptor, 2 – 2 million gallon Southwest “B” reservoirs, a 15,000 gpm pump station, and Southwest “A” storage reservoir site development, 12,000 lineal feet of 24” – 48” water transmission main. Work included environmental assessment, platting, survey coordination, design, approvals, and construction support. Project received Environmental Award from the City of Austin.
Intake structure on Lake Austin and 0.86 mgd water treatment plant – Work included planning, survey coordination, design, approvals, and construction support.
Project included approximately 6,650 linear feet of 12-24 inch wastewater trunk line. Work included planning, survey coordination, design, approvals, and construction support.
Line was approximately 7,500 linear feet of 18-30 inch water line including two bores under US 183. Work included planning, survey coordination, design, approvals, and construction support.
Project included water, wastewater, and drainage improvements for the Lakeline Development in the right-of-way of Pecan Boulevard, Lakeline Boulevard, and Stonestop Boulevard. Work included planning, survey coordination, design, approvals and construction support.
Station was a 7,000-gallon per minute station for North Austin Municipal Utility District #1. Work included planning, survey coordination, design, approvals, and construction support.
MUD needed 300,000 gallon per day first phase wastewater treatment plant, 2,400 gallon per minute well system, elevated reservoir, and transmission and approach mains for the North Travis County MUD #5. Work included planning, permit preparation and application, survey coordination, design, and approvals.
The Cottonwood Wastewater Treatment Plant utilizes the membrane bioreactor process (MBR) designed and constructed around the Kubota flat plate membranes and Enviroquip, Inc. components. This facility has a permitted capacity of 2.0 MGD but is currently constructed for operation up to 0.5 MGD. It is understood that this facility is currently the largest MBR facility in operation in Texas today. Situated just southeast of the City of Manor, Texas, this facility was financed by Southwest Water Company to provide service to areas within its CCN which includes the Cottonwood MUDs located north of the City of Manor. High quality effluent with limitations of 5 mg/L BOD5, 5 mg/L TSS, 2 mg/L NH3-N, and 1 mg/L phosphorus is discharged to Wilbarger Creek thence to the Colorado River downstream of Austin, Texas.
The Forest Creek Wastewater Treatment Plant is situated near Pflugerville in Williamson County, Texas, and is owned and operated by Windermere Utility Company (WUC), a wholly owned subsidiary of Southwest Water Company. This relatively small wastewater treatment facility was originally designed and constructed to service a resident/retail district located north of the city of Pflugerville and is currently in the second phase of a multi-phase expansion. MEC designed and oversaw construction of the first phase of the treatment works (0.2 MGD), which served primarily residential development. With increased demand for retail/commercial development and particularly a full-service flagship grocery store, it became obvious that this utility would soon receive organic load concentrations above the existing design parameters and that the plant would become organically overloaded. MEC was employed to investigate the concerns and make recommendations. The preliminary engineering report determined that under the projected loading the aeration basin would be organically overloaded and the design flow would thus be reduced. Following the recommendation of the preliminary engineering report, WUC retained MEC to expand the plant to accommodate the anticipated loading and amend the existing TPDES permit to reflect the recommended phasing schedule. MEC secured the permit amendment and designed a 0.5 MGD expansion for a 10 mg/L BOD5 and 15 mg/L TSS, single-stage nitrification wastewater treatment plant expandable to 1.0 MGD using a common wall. The existing concentric “bull’s eye” plant was converted to an aerobic digester and gravity thickener.
The TCMUD 4 South WTP is a 2 MGD water treatment plant, expandable in 2 MGD increments to 8 MGD, that has been designed to serve the southern area of the Barton Creek development in Travis County. The plant includes a raw water head tank, solids contact clarifier, dual media filters with inter-cell gravity backwash, transfer pumps, clearwell, high service pumps, and a 0.5 MG elevated reservoir. Disinfection is by free chlorine in the head tank followed by chloramines through the treatment processes and into the system. Ancillary equipment includes a “water-saver” basin where the clarifier blowdown, filter backwash, and filter-to-waste water all gravity flow into a decant basin. After a period of time for settling, the clarified decant water is pumped back to the head tank while the settled sludge is periodically wasted into the regional wastewater system. The water treatment plant design incorporates on-site and remote communications, automated controls, alum, chlorine, LAS, and polymer storage and feed, automated disinfectant and turbidity monitors, and plant data collection, analysis and alarms.
The existing raw water delivery system was experiencing capacity and high pressure problems. The solution was to design and construct an intermediate pump station set between the intake raw water pump station and the delivery point and to trim the existing pumps impellers, increasing the overall system capacity and decreasing the delivery pressure from the intake pump station.
The existing system delivered water from the intake pump station to a surge tank, located on top of a watershed divide, where the raw water flows by gravity into the District and its water treatment plant. The pumps operation was based on the water level in the surge tank as relayed to and through a RTU that also controlled the lake pumps and monitored the pump vibration sensors. The intake pump station communicated with the surge tank using two leased phone lines (one for back-up) and the delivery system data was relayed to the water plant’s control computer from a radio at the surge tank.
The intermediate pump station included a ground storage tank and VFD driven vertical turbine pumps. The pump control now maintains a set level in the surge tank using a PID algorithm and the intake pumps, with trimmed impellers, are controlled by the water level in the new ground storage tank at the intermediate pump station site.
This project involved the planning, coordination, and design of an expandable potable water pump station, 18,000 linear feet of 16-inch water line, a receiving ground storage reservoir and hydropneumatic booster pump station with spur waterlines from the hydropneumatic station that allowed the LCRA to expand its West Travis County water system along Hamilton Pool Road. Planning involved identifying major immediate end users, which would allow project funding feasibility, and coordinating the design of the facilities to include an expansion potential to match the projected long-term LCRA water system plan for western Travis County.
The pump station is a quad station that can isolate each pair of pumps so that four pumps may pump to the ground storage reservoir station (current operation) or allow the pumps to pump into two different sub systems (future). For the current operation, the pumps have to be capable of supplying the receiving reservoir, which sets a pressure plane that physically exists both in front of and behind the pump station, and to not trip on pressure surges when flow reversals occur in the main line at the pump station when the back side of the pressure system demands water. Also, while the installed pumps are each 750 gpm, the piping, pads, and electrical systems were sized to allow change-outs to 1500 gpm pumps in the future. At the other end of the line, a 0.25 million gallon ground storage reservoir receives the water and a 15,000 gallon hydropneumatic tank with pumps and controls provides a pressure system to higher elevations west of the ground storage reservoir. Both systems are linked into the LCRA’s SCADA system with pertinent information communicated between these two sites and replayed back to the central communication unit at the LCRA’s West Travis County Water Treatment Plant. The project is constructed and being operated by the LCRA.
The original Windermere Wastewater Treatment Plant consisted of precast concrete basins providing a capacity of 1.0 MGD for a permitted effluent of 20 mg/L BOD5 and 20 mg/L TSS. MEC engineers were employed to assist the facility owner, the former ECO Resources, Inc., with assessment and design services to expand the capacity to 2.0 MGD and eventually to 3.0 MGD and to prepare and process a permit amendment application. With this permit renewal, effluent limitations were revised to 5 mg/L BOD5, 5mg/L TSS, 2 mg/L NH3-N, and 1 mg/L phosphorous. These more stringent parameters implied additional aeration and the installation of phosphorus removal facilities and effluent filters. Following an inventory and assessment of the existing cast in place basins and owing to the more stringent effluent limitations it did not appear feasible to expand the existing facilities into an operationally or cost efficient facility. Instead, it was decided to construct a new 2.0 MGD facility capable of providing biological phosphorus removal and effluent filtration. The design also included an anoxic basin for nitrate reductions and denitrification. The existing cast in place concrete basins were converted to aerobic digesters, Digested sludge is thickened with a centrifuge and dewatered to cake through a belt press.
The Sunfield Wastewater Treatment Plant is a 0.25 MGD wastewater plant, expandable in two additional phases to 1.0 MGD, serving the Sunfield development east of Buda. The WWTP was developer funded and is intended to serve the early years of the Sunfield development until such time that the approximately 2600 acre development requires capacity in excess of 1 MGD and a regional, and more permanent, plant is constructed on the 17 acre site. Because the WWTP was developer funded, low initial costs were important. Concentric steel tankage and an extended aeration with alum addition and tertiary filters mode of operation were chosen for cost, ease of operation and to achieve the stringent effluent limitations required by the State permit.
The WWTP includes an influent lift station, extended aeration treatment basin, gas chlorination disinfection, cloth disc filtration, effluent holding pond and an effluent pump station. Ancillary components include alum and chorine storage and feed, sound attenuated rotary lobe positive displacement blowers, influent bar screen and splitter box designed to incorporate the future phases, and an in-plant treated-effluent water system. The influent lift station includes two batteries of pumps, one set being controlled by VFDs and one set being full RPM, to help pace the raw water flow into the plant.