News | June 25, 1999


Source: Fluidyne Corporation
Fluidyne Corporationpany%>has provided Campestre Torreon the first Sequencing Batch Reactor in Mexico that turns municipal wastewater into irrigation water.

The Decision:

Mexico's National Water Commission has recently implemented a series of measures intending to preserve the precious water in the area. The agency increased taxes on aquifer removal rights, encouraged utilization of treated wastewater especially for crops and gardens and promoted well-water use for only human consumption in areas of most need.

The administrative body at Campestre Torreon determined that it was not possible to continue to irrigate the golf course with well water, realizing that there was a greater need for potable water in other sectors of the city. The engineers decided that they would reclaim wastewater from the city sewer and use that as their irrigation source.

After much deliberation, it was determined that the Fluidyne Sequencing Batch Reactor would be the ideal treatment system. Campestre Torreon based the decision on several key factors:

  1. Ability to maintain the ecosystem in their man-made lakes due to high quality effluent;
  2. Lower capital costs over other processes;
  3. Minimal operator attention and time; and
  4. Ability to surpass the necessary levels of BOD, TSS, and greases/oils needed for irrigation.

The Design:

Fluidyne's SBR was designed to treat 3200 m3/day (864,000 gpd) from the city's sewer line. Influent BOD, TSS, and greases/oils levels were based on 250 mg/l, 300 mg/l and 100 mg/l respectively. The NWC has set standards for treated effluent used for irrigation. These are 30 mg/l BOD, 50 mg/l TSS and 20 mg/l greases and oils. Disinfection after treatment was required to control algae and bacteria growth in the lake and to eliminate the high levels of fecal coliforms.

The Process:

From the city line the raw sewage is directed to a primary basin where solids can settle before treatment. Then the liquid travels to a dual tank SBR system. As one tank fills, the other tank proceeds through the different cycles of the SBR. The contents of the tank are mixed and aerated using Fluidyne's high efficiency FRP jet headers. When a tank reaches top water level, inflow is diverted to the other tank so that biological reactions can be completed in the full tank. Then the biological solids settle and the clear liquid is decanted through a Fluidyne FRP Solids Excluding Decanter.

From there the decanted liquid travels through a Fluidyne FRP disinfection system where chlorine is added and mixed by a jet nozzle into a reactor tube. All the above functions are regulated by a programmable logic controller. After disinfection, the effluent flows to a storage tank and then it is pumped to a lake on the golf course where the water can be reused.

The Campestre Torreon wastewater treatment plant has now been in operation for almost a year and a half. The SBR has easily surpassed all NWC standards. Even the higher than expected grease and oil influent levels are being reduced by over 97%. The Industrial Metallurgic Laboratory in Mexico tested the effluent quality. The results can be seen in the Table below.



Effluent to lake

Greases & Oils

174 mg/l

4 mg/l


290 mg/l

2 mg/l


200 mg/l

2 mg/l

The Conclusion:

In a country such as Mexico where water is considered so valuable, the Fluidyne SBR now allows a city to take well water that was once used for irrigation and provide it to 2500 additional families. Probably the best way to show the treated wastewater is of high quality is the presence of 3000 to 4000 migratory ducks o n the irrigation lake and a thriving fish population in the lake.

The Fluidyne SBR is also beneficial to Campestre Torreon in an economical sense. The golf course now does not have to pay high fees for well water rights. Campestre Torreon expects to recover their investment with the Fluidyne SBR in four years.