City of Yankton Seal City of Yankton Seal
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City of Yankton - Water Treatment Project


Water Treatment Plant Project Presentation

Water Treatment Plant #1

Below are links to view the Powerpoint presentation about the proposed water treatment plant improvements. Additional materials will be added to this page to help answer questions and provide information about the proposed project to the public.

For more information, please contact the City of Yankton Water Treatment Plant at 668-5272.


Below is a link and demonstration video for the Ranney® collector well. The video shows the process for the test wells and how the collector well will be constructed.

Ranney® Collector Well Construction





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Frequently Asked Questions

What are the major factors driving this project?

  1. Demand

    It is estimated that current infrastructure will no longer meet our water demand as early as 2015. This is due to increases in both population and usage. Capacity to our system has not increased since 1972.

  2. Intake Damage and Changes to the River

    Damage to the intake and continual changes to the river is another issue the City faces. The intake was damaged in the 2011 flood due largely to a sandbar built up underneath the structure. The channel of the river changed with the flood, making it difficult to intake the same amount of water as we were able to prior to the flood. Drought conditions and low release rates from the US Corps of Engineers also negatively impact our ability to intake water.

  3. Regulatory Issues

    Regulatory issues are another reason improvements are being considered. We had several years of quarterly violations with Trihalomethans (by-products from chlorine disinfection reacting with organic materials that are abundant in our river). According to the EPA and SD Department of Environment and Natural Resources, improvements are necessary to avoid ongoing violations.

  4. Aging Infrastructure

    We also need to take into consideration the fact that our peaking plant was built in 1929 and our base load plant was built in 1972. Because of the aging infrastructure, major upgrades are needed to continue to meet demand and regulatory issues. Both plants have obsolete technology with parts and equipment which are very difficult to replace when repair is needed.

  5. Redundancy

    The City of Yankton is also concerned about redundancy within our system. The 1929 plant has a treatment capacity of 3 million gallons per day. The 1972 plant has a 5 mgd treatment capacity. We have peak days in the summer over 7mgd. The concern is the critical water usage during the summer months. We believe the water critical for drinking, hygiene, industrial, commercial, emergency care, and fire protection has exceeded 3mgd. Therefore, if equipment failure at Plant 2 shuts down the facility we would only have 3mgd available. This could result in water restrictions that could be very expensive for industrial and commercial users and at best inconvenient for personal users. Our goal is to have a peaking plant capable of supplying enough water to at least meet our critical usage.

What is the current treatment capacity?

The 1929 water plant has a 3 million gallon per day capacity. The 1972 treatment plant has a 5 million gallon per day capacity. Total 8 million gallons per day. What is our current source water capacity. The Nebraska well field has two wells capable of producing 4.2 million gallons per day. The river intake is capable of producing 5.5 million gallons per day but has become unreliable due to changes in the river. To treat 8 mgd you need 9 mgd of raw water.

What is our current and future demand?

Our current demand ranges from 2.0 million gallons per day to a peak day is 7.5 million gallons per day. The predicted peak demand is 8.2 million gallons by 2015, 9.1MGD by 2025, and 10.0MGD by 2035.

Why design for peak usage?

We design for peak usage so we can meet the demand of the customers at all times. This also gives us the redundancy and reliability need to meet the critical demand during scheduled and unscheduled repairs and maintenance.

What is critical demand?

The critical demand is the water needed for necessary uses for residential, commercial and industrial use.

Why not drill another well in Nebraska?

The collector well at Paddle Wheel point was determined to be the most reliable and long term cost effective source of supply. The collector well has both high capacity and higher water quality than the Nebraska wells. The collector well will not be influenced by the changing river or changing river levels.

Why not build the new plant at Paddle Wheel Point?

The new plant will take advantage of existing clearwells and underground reservoirs located between the current plants. The new treatment plant will also be able to take advantage of the distribution system already in place at the current location. A plant at Paddle Wheel point would require a reservoir and major upgrades to the distribution system in that area, greatly increasing the cost.

What is a collector well?

These wells are generally comprised of a vertical reinforced concrete shaft (caisson) with horizontal lateral well screens projected out into the aquifer to collect and filter the groundwater. Collector wells are the preferred method for developing moderate to very high capacity riverbank filtration (RBF) supplies. RBF Collector wells can be installed adjacent to surface water sources with their lateral well screens projected beneath the riverbed to optimize induced infiltration supplies or they can be installed with designated setback distances to increase the degree of filtration achieved.

Why doesnít the City move the water treatment plant out of Riverside Park / riverfront area?

Relocating the water treatment facilities is not cost effective.

If we were to move all of our facilities to the Paddle Wheel Point location, the estimated cost would be approximately $50- $60 million. The cost would include a new 10 MGD water treatment plant, a new collector well for reliable water supply source, extension of a raw water transmission main from the Nebraska wells to new plant and distribution system upgrades.

Why not build the new plant expansion at another location?

The City could build the new plant at a different location as a compliment to the existing Plant #2. The cost would be $5.5 million dollars in addition to the proposed $29 million dollars for the collector well and treatment facility. The location change would require a wet well, pump station and finished water transmission main from the new location to Plant #2. In this scenario, we would still have a major capital expense (up to the estimated $50-$60 million dollars) of moving the water treatment facility plant #2 , at such time that it warranted decommission.

Should the City of Yankton purchase Water from B-Y Water?

The purchase of B-Y Water is not cost effective at this time.

The following items are key in evaluating the Cityís potential purchase of B-Y Water

Other factors to consider when analyzing the purchase of water from B-Y:


Kyle Goodmanson, Director of Environmental Services
email:kgoodmanson@cityofyankton.org
315 West Riverside Drive
PO Box 176
Yankton, SD 57078
Phone: (605) 668-5272