Field Trip to Springfield Wastewater Treatment and Landfill
/The last field trip on the Missouri Master Naturalist (MMN) training schedule was to the Springfield Wastewater Treatment Plant and Landfill.
The wastewater treatment plant that we toured was the smaller of the two that handle Springfield’s sewage. I was surprised that the smell of the place was not as bad as I expected. Maybe it was not as bad because it was a cool morning, but I expect that it primarily was because of the improvements in technology since I last toured a plant over 50 years ago! Now they have a lot more filters and blowers. There are challenges of materials that shouldn’t be in sewage – small items that get flushed (including wipes) that are still solid when then get to the plant and those are taken out early. There are anaerobic and aerobic basins where microbes do the work of cleaning the water. Sometimes there are enough oils that they must be put back through the process. Once the sludge is taken out, the water is clear and the microbes remaining are killed using UV light before the water leaves the plant for the river; the water released from the plant is about the same water quality as the river and there is monitoring to make sure that is true.
The landfill is uphill from the wastewater plant; the landfill is a high hill so there are great views of the countryside around it.
It was a learning experience…I took notes. The landfill is 1200 acres of land with 213 acres active (i.e. there is plenty of buffer between the landfill and neighboring properties). We learned about the landfill’s construction that protects groundwater; the liner under each cell of the landfill is 5 foot thick: compressed aggregates, felt, plastic, leachate pipe (to drain of liquids) surrounded by river gravel, and finally felt. Each cell of the landfill is 5-10 acres. The leachate pipes are connected to a sewage line that takes the fluid down the hill to the wastewater treatment plant. The temperature in the landfill is 100-120 degrees and that is monitored via wells that are extended as pile gets higher. There are 16 ground water wells near the landfill that are checked every 6 months. They have increased the number of gas wells from 97 to 148; at present the methane is flared because it is not clean enough to put into natural gas pipelines (and it evidently is expensive to get it clean enough). The landfill had been projected to last 100 years when was expanded to 213 active acres but then the pandemic happened, and the projection is now 50 years (we are sending a lot more to the landfill since the pandemic). The city is more actively trying to divert yard waste away from the landfill and promote composting of food scrapes/waste.
The landfill layers quickly become anaerobic because of the heaps of trash piled and compacted. There is a lot of plastic that does no decompose easily even in aerobic conditions and even things that would decompose in aerobic conditions don’t in anerobic. These hills of trash are going to be where they are built for a very long time.
I am thinking about what further changes I will make after this experience. My family tends to have more recycle than trash. The change for me might be that I take more of my recycle to the recycling center rather than doing my curbside bin. Evidently there are lots of things that can happen during mixed stream recycle processing that can result in materials to the landfill.
