Tag Archive for: dewatering systems

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Killing me softly with…PVC

Final installment of a series examining the impacts of a “dewatering system” on an eco-system. The series began with “We have met the enemy and he is us” This post introduces the topic of the impacts of a “dewatering system” on the infrastructure of a city. Part II “It’s all related” continues the discussion with the impacts on water and rivers. Part III of the series “What watt?” looks at the direct and indirect energy use resulting from the installation of the system and the resulting CO2 emissions.

PVC or Polyvinyl Chloride seems to be everywhere these days. It’s in everything from electric wires, to toys, to portable electronic devices and of course pipes. The “dewatering system” installed underneath the new 1,000 Marriott Hotel in downtown Indianapolis consists of almost 5,000 feet of PVC pipes. These pipes are used to gather the naturally occurring groundwater and funnel it to the sump basins where it is then pumped into the Indianapolis sewer system.

PVC has been the subject of a lot of attention since its first commercial uses in the 20’s and 30’s. Throughout its lifecycle (manufacturing, use, and disposal), it has been linked to various health issues including cancer, birth defects and reproductive impairment. Many of the environmental and health issues stem from the additives used to soften the normally rigid material.

During the manufacturing process workers exposed to the vinyl chloride face an increased risk of cancer of various types. Since the link between the vinyl chloride and the cancer in workers was discovered in the 1970’s, changes in the manufacturing process have virtually eliminated the exposure to the workers. Virtually eliminated…I don’t know about you, but virtually eliminated does not make ME feel warm and fuzzy, nor does it make me want to go to work in one of those factories. However, the danger does not stop at the factory doors. The EPA found “vinyl chloride emissions from polyvinyl chloride (PVC), ethylene dichloride (EDC), and vinyl chloride monomer (VCM) plants cause or contribute to air pollution that may reasonably be anticipated to result in an increase in mortality or an increase in serious irreversible, or incapacitating reversible illness. Vinyl chloride is a known human carcinogen that causes a rare cancer of the liver.”

Another problem with PVC is its tendency to leach and off-gas its chemicals. Leaching is a process by which the carcinogens and other poisons transfer to other things that come in contact with them. This was discovered to be a significant problem in such things as soft toys that would be chewed on by infants and even in (sorry mom) some adult “toys” as well. This has led to bans on various additives in some products. Studies have shown that chemicals in the PVC can even leach into water as it moves through a pipe. Off-gassing, is the process in which these poisons are released into the air. You know that new car smell? Yep, you guessed it…off-gassing! NOT a good thing. This has led to various manufacturers (Toyota, Nissan, Microsoft and others) to eliminate PVC from their products. It has also led to retailers either reducing the number of PVC products they carry or eliminating them altogether.

Finally, disposal…products made from PVC are very difficult to recycle. Since they are made up of various additives, the process to break down the material into useful components is costly, inefficient and only so successful. Most of the products made with PVC end up in being disposed of by the consumer, either by burning it with their trash, or throwing it away in their trash, where it might go to a municipal incinerator or to a landfill. What is significant about this is the fact that when burned, PVC releases all kinds of toxic chemicals into the air, like hydrogen chloride and dioxins. (Do you know how common landfill fires are?)

If all these things are wrong with PVC, why is it still in use? The answer is simple…it’s CHEAP! Human Health vs. the Dollar…now THAT discussion is a whole other BLOG!

Conclusion-

So dear reader, I hope you have stuck with me through this series of articles. I hope they underscore the synergistic nature of our environment and the need to consider ALL impacts when trying to solve an issue. What first looks like the fast, easy, and inexpensive way out may prove to be just the opposite. Finally, I hope they inspire you to get involved in your community by asking why things are done they way they are done and seeking better and better ways to live on this planet without killing it (and ourselves).

 

 

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What watt?

Part Three of a Series: “We have met the enemy and he is us” introduces the topic of the impacts of a “dewatering system” on the infrastructure of a city. Part II “It’s all related” continues the discussion with the impacts on water and rivers.

So what does a water issue have to do with energy? Simple, you may recall from the previous posts, that the new Marriott Hotel being constructed in downtown Indianapolis has a parking garage that is three floors below grade (underground). The third floor extends below the top of the water table which required the installation of four pumps to extract the water and send it into the sewer system. These pumps run 24 hours a day, seven days a week, 365 days a year (and sometimes 366).

Now, I don’t know what types of pumps are installed in the Marriott or the size of the pumps nor am I an electrical engineer. However, it is reported that they are pumping a total of 1,200 gallons per minute, or 300 gallons per minute per pump. I doubt very seriously that they sized the four pumps right at 300 gpm, but let’s say for a minute they did. A quick internet search finds that a typical industrial dewatering pump capable of pumping 300 gpm requires about 460 volts of electricity and draws about 20 amps. That is the equivalent of 9.2 kWh (kilowatts per hour). Four pumps running 24 hours a day comes to about 900 kWh every day. As a comparison, the average American family uses 938 kWh every day. So, every day, the pumps use enough electricity to power a house.

As I mentioned, they probably did not size them at the bare minimum. Perhaps they put in 600 gpm pumps. One of those pumps uses 460 volts and draws 54 amps. That is almost 25 kWh per hour per pump. Four pumps running 24 hours a day would use about 2,400 kWh a day, or enough to power about 2.5 households.

We can’t have a discussion about energy use without mentioning CO2 emissions. This amount of electricity produces from 236 metric tons of CO2 a year on the low end to 629 metric tons on the high end. That is the equivalent CO2 of between 43 and 115 cars on our roads…from the dewatering pumps of one building in one city.

And since 96% of Indiana’s electricity comes from coal, consider the other impacts of burning coal…air pollution (beyond carbon), water pollution, sludge creation and storage.

There are indirect energy impacts as well. Since all of this water is being pumped (presumably) into the Combined Sewer system it has to be processed as wastewater. A typical wastewater treatment plant burns 6,000 kWh of electricity to process each million gallons of water. As we know, these pumps are flushing 1,728,000 gallons a day into the system or about 630,720,000 gallons a year. How does 3,784,320 kWh of power sound? That’s almost 11 more households of electricity. And carbon? How does another 2,195 metric tons of carbon sit with you? ANOTHER 400 cars!

Keep in mind; this is all to move water that didn’t have to be moved in the first place!

Stayed tuned for the final installment in this series, “Killing me softly with…PVC”.

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What watt?

Part Three of a Series: “We have met the enemy and he is us” introduces the topic of the impacts of a “dewatering system” on the infrastructure of a city. Part II “It’s all related” continues the discussion with the impacts on water and rivers.

So what does a water issue have to do with energy? Simple, you may recall from the previous posts, that the new Marriott Hotel being constructed in downtown Indianapolis has a parking garage that is three floors below grade (underground). The third floor extends below the top of the water table which required the installation of four pumps to extract the water and send it into the sewer system. These pumps run 24 hours a day, seven days a week, 365 days a year (and sometimes 366).

Now, I don’t know what types of pumps are installed in the Marriott or the size of the pumps nor am I an electrical engineer. However, it is reported that they are pumping a total of 1,200 gallons per minute, or 300 gallons per minute per pump. I doubt very seriously that they sized the four pumps right at 300 gpm, but let’s say for a minute they did. A quick internet search finds that a typical industrial dewatering pump capable of pumping 300 gpm requires about 460 volts of electricity and draws about 20 amps. That is the equivalent of 9.2 kWh (kilowatts per hour). Four pumps running 24 hours a day comes to about 900 kWh every day. As a comparison, the average American family uses 938 kWh every day. So, every day, the pumps use enough electricity to power a house.

As I mentioned, they probably did not size them at the bare minimum. Perhaps they put in 600 gpm pumps. One of those pumps uses 460 volts and draws 54 amps. That is almost 25 kWh per hour per pump. Four pumps running 24 hours a day would use about 2,400 kWh a day, or enough to power about 2.5 households.

We can’t have a discussion about energy use without mentioning CO2 emissions. This amount of electricity produces from 236 metric tons of CO2 a year on the low end to 629 metric tons on the high end. That is the equivalent CO2 of between 43 and 115 cars on our roads…from the dewatering pumps of one building in one city.

And since 96% of Indiana’s electricity comes from coal, consider the other impacts of burning coal…air pollution (beyond carbon), water pollution, sludge creation and storage.

There are indirect energy impacts as well. Since all of this water is being pumped (presumably) into the Combined Sewer system it has to be processed as wastewater. A typical wastewater treatment plant burns 6,000 kWh of electricity to process each million gallons of water. As we know, these pumps are flushing 1,728,000 gallons a day into the system or about 630,720,000 gallons a year. How does 3,784,320 kWh of power sound? That’s almost 11 more households of electricity. And carbon? How does another 2,195 metric tons of carbon sit with you? ANOTHER 400 cars!

Keep in mind; this is all to move water that didn’t have to be moved in the first place!

Stayed tuned for the final installment in this series, “Killing me softly with…PVC”.

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It’s all related!

In my previous post “We have met the enemy and he is us“, I discussed the “dewatering system” that was built for the new Marriott Hotel in downtown Indianapolis and the impact this system will have on the Combined Sewer Overflow system. Today, let’s examine some of the other impacts this system and others like it have on our environment.

John Muir once said “When one tugs at a single thing in nature, he finds it attached to the rest of the world.” What this means is all of the systems in nature are interrelated and changes in one area can have dramatic impacts in others, in other words, when we try to outsmart nature, we inevitably screw something else up! This “dewatering system” is an excellent example; there are impacts, not only to the water systems, but also to energy, carbon emissions, human health and wildlife survival.

Water – Forget the fact that these pumps are taking what could be perfectly good drinking water (or at the very least perfectly good “process” water) and flushing it down the drain, there are other impacts to the water systems. Because the parking garage in this example was built below the water table, pumps run continuously to pump the naturally occurring groundwater into the sewer system. The effect of this pumping is to lower the water table in the area, and potentially in a large surrounding area. When the water table is lowered several things occur. First, anyone in the area that is using well water will find that their wells go dry as the water table lowers, thus requiring them to dig their wells deeper, sometimes at great expense. Next, as the water table lowers, water, being water, will follow the path of least resistance and begin to “fill in” the area. This means groundwater from a larger area will begin to move thus impacting larger and large areas. In some cases, nearby wetlands and rivers could begin to drain and dry up.

In addition, as the water table lowers, plant life that is dependent upon that water will begin to die out as its root system can no longer reach its water source. This may require additional irrigation to keep the plants alive which adds to the vicious cycle and strain on the water system. In some cases, invasive plants will migrate into the spaces left behind by the dying plants. Wildlife that depends on the native plants will die out or migrate to other areas due to lack of food.

Among the impact caused by lowering the water table is subsidence. Because the presence of ground water creates hydraulic pressure, it is able to support the weight of the soil, rock, AND BUILDINGS above it. Removing the groundwater will cause a “sinking” or settling of the earth above it. Don’t believe me? The city of San Jose is THIRTEEN feet lower today than it was 100 years ago. The problems in New Orleans were exacerbated in part by subsidence caused by the extraction of groundwater over the last century. What will be the impact to the buildings as the ground around them SINKS? They too will sink and settle causing foundation problems, and other structural and non-structural issues throughout the building or HOME!

River – While we are talking about water, let’s look at the impact on the river. According to the senior manager on the project for Marriott, the water was going to the river any way, well was it? Ground water is replenished by rain water, surface water, AND NEARBY RIVERS AND STREAMS. This water may have COME from the river not be on its way TO the river. As the water table lowers, the river could try harder and harder to refill the void, eventually drying up the river. It has happened before folks! However, let’s assume for the moment that the manager was right and the water was heading to the river. By “speeding up the process” the ecosystem of the river will be changed. Rather than the water slowly filtering through the ground (and being naturally cleaned and filtered along the way) it will be blasted into the river. This will lead to increased erosion as the water speed is faster than is natural. The increase in erosion will lead to additional sediment in the water (already the number one pollutant in Indiana). This increase in sediment will begin to kill off the fish and plant life in the river as they can no longer find food or the food dies off because of lack of sunlight that is now blocked by the sediment. In addition, many of the organisms that serve a key role in the food chain are impacted by even slight changes in water temperature. Because this water did not reach the river naturally, it will change the temperature of the water.

Energy – What a minute, I thought we were talking about water here, what does that have to do with energy? In my next post we will discuss the energy impacts (both direct and indirect) of the “dewatering systems”.

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