It is always a pleasure to work with you to educate our operators here in Wyoming about the need to properly maintain wastewater treatment lagoons.
There are many factors that impact the performance of wastewater lagoons. The most important by far is to have an adequate microbial population so that the wastewater can be properly treated and stabilized to minimize the impact on the receiving streams.
Over the past several years, I have performed numerous sludge profiles around the state, most of which share the same problems, excessive sludge accumulations.
From my follow ups to these systems, it is obvious that the addition of microbes to the wastewater have had a positive impact on the appearance of the wastewater treatment lagoon as well as sludge reductions.
For example, the small amount of money that has been spent on microbial products has saved systems much more in dredging costs. These microbial additions not only reduced sludge volumes, they have also helped systems return to compliance.
I calculated to cost savings at current dredging costs of S300 per dry ton. Cody, WY in 2004 was in need of dredging their lagoons at a cost of range of S946,519 to SI, 114,575.
In 2009, the cost to dredge was $513,707 to $642,134. This at face value saved the system S432,818 to $472,441 over this five year period. We must also consider that by getting a reduction in sludge we also saved the system additional engineering cost as well as the cost to build an additional pond.
This cost could easily reach an additional $250,000. We also need to discuss how the microbiological additives prevented a complete overhaul of the filtration system since these additive were able to break down the sludge within the under drain piping system at a cost likely to reach an additional $250,000.
Finally, we were able to prolong dredging so far for 5 years and could easily be another 5 to 10 years before dredging is required.
If they would have dredged in 2004 the City of Cody would likely be 10 to 15 years away from dredging again. Today, the savings to the City of Cody are in the range of $932,812 to $972,441.
In 2020, when the system could need to be dredged, the cost savings could range between $1,750,000 to S2,000,000 including inflationary costs.
Registered Wastewater Technician
WY Assoc, of Rural Water Systems