Step 1:
Collection
As influent first enters the plant, sand, silt, gravel, and other inorganic materials entering the system from area homes and business are removed from the waste stream. These materials are sent out for disposal at a local landfill.
Step 2:
Settling
Influent then flows into one of four primary clarifiers—essentially large settling basins. With the help of chemical coagulators, mid-sized organic and inorganic particles clump and settle out of the waste stream. These particles are removed, and the cleansed water and any remaining particles move on to Second Stage treatment.
Step 3:
Division
At this point, influent is split between two plants: about ¾ of the flow goes to our west plant, and the remaining ¼ goes to our east plant.
Step 4:
Treatment
At both locations, we employ a process called “activated sludge”-one with high-purity oxygen, and one with naturally occurring air. We inject the wastewater stream with these gases to create an environment perfect for micro-organisms to thrive. These micro-organisms do most of the remaining work for us, feeding on whatever organic solids may be left in the stream before settling out in one of the plant’s six secondary clarifiers.
Step 5:
Disinfection
From here, the flow enters our chlorine contact tank, where it is disinfected with sodium hypochlorite, liquid bleach, and sent to the James De Young Power Plant to be used as cooling water before ultimately returning as clean water to Lake Macatawa. This reuse allows the power plant to use fewer chemicals and less water from the lake.
WASTEWATER PIPE PATCH
We're always exploring innovative ways to improve the reliability of our services.
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The Holland Board of Public Works is always exploring innovative ways to improve the reliability of our services.
Last year, we purchased equipment that allows our crews to make repairs to sanitary sewer mains remotely, eliminating the need for expensive and disruptive excavations and improving safety. These patches maintain the integrity of our system, keeping clean groundwater out of the wastewater stream that would otherwise be treated unnecessarily, increasing the strain on our wastewater treatment plant.
Within 6 months, the equipment had paid for itself after just five repairs.
LIFT STATIONS
We're working hard to improve the reliability of our lift stations, which are instrumental in collecting wastewater from all around our service area.
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Our lift stations help to get sewage to the wastewater treatment facility from the furthest reaches of our service area.
In order to ensure that our lift stations continue to function as needed, we conducted evaluations of each of our lift stations to assess their reliability. From there, we developed a capital improvement plan that will allow us to make adjustments at these lift stations to improve their reliability, from modifying pumps to installing new backup generators.
WASTE TREATMENT PLANT HEADWORKS
Our new headworks facility will increase our efficiency by doubling our influent capacity.
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In 2010 we began construction on our Headworks Improvement project: a re-engineering of the way influent is handled at our wastewater treatment plant.
Currently, two separate waste streams feed our facility: one from the north and one from the south. The new Headworks facility will combine these streams prior to entering the processing plant and remove grit and inorganic debris greater than ¼” from the combined waste stream. Removal of these solids protects downstream equipment and will greatly reduce the time and money spent on repairs.
In addition to vastly improving
the plant’s reliability, this project will increase the plant’s hydraulic capacity from 24 million gallons per day to more than 30 million gallons per day. This forward-thinking design will allow us to further expand our wastewater treatment capabilities as needed as future demands grow.
Construction is almost completed, and we expect the facility to be fully operational by December 2011.
INVESTING IN BUSINESS GROWTH
We've increased our output and support to the LG Chem and Johnson Controls-Saft plants.
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LG Chem and Johnson Controls-Saft decided to come to Holland in part because of the Holland Board of Public Works’ outstanding reliability and low rates. In order to support their investment in our community, the Holland Board of Public Works undertook several new projects.
This year, the Holland Board of Public Works increased the capability at two substations by more than 40 MW by installing two new transformers to help bring power to LG Chem and JCI-Saft. Additionally, the Holland Board of Public Works extended water and wastewater mains to service these plants.
These plants are an investment in the future of our community and alternative energy, and the Holland Board of Public Works is pleased to support them with high-quality, reliable utilities.
WATER & SEWER MAIN REPLACEMENTS
We're replacing deteriorated water mains along 40th Street and at other locations, greatly reducing the number of blockages these customers experience.
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Whenever possible, the Holland Board of Public Works collaborates with the City of Holland to reduce cost and disruption, both for the City and for our customers.
Customers along 40th Street between Central Ave. and Washington Ave. encountered several water main breaks each year due to deteriorated mains. Working with the City of Holland, we replaced these deteriorated mains with new ductile iron mains wrapped in polyethylene, offering far greater durability and corrosion protection.
We also performed similar replacements on 18th Street
between Cleveland and River Avenues, and on Harrison between 18th and 19th Streets. Replacing aged sanitary sewer mains improves reliability and performance of our sanitary sewer system.
The Holland Board of Public Works is always looking for ways to better serve our community, and projects like these allow us to do so.
