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CASE STUDY:

Chain Restaurant

New McDonald’s Restaurant
Sanford, Michigan

Facilities:

McDonald’s Restaurant with Shell gas station/Convenience store.

"The biggest issue was finding the right system to fit the site. After exhausting many weeks and multiple work hours of discussion and research we decided to try the Nibbler® system, mainly due to NCS experience and track record working with McDonald’s in other regions of the country."

Gene Oberlander
McDonald’s Corporation - Construction Project Manager

Site Details:

Vacant parcel of land located off of Highway 10 near Sanford, Michigan. Site conditions were extremely difficult due to a high water table. The water table was only 2 to 3 feet below grade, which made excavation and tank setting very challenging. Providing watertight tanks would be critical. (Tanks supplied by Advanced Concrete Products Co. located in Highland, MI). Access to the site was limited for excavating and tank setting equipment. This not only created challenges for the installation of the wastewater treatment system, it also created numerous building construction challenges for erecting the restaurant.

Client Requirement:

• Design and install a wastewater treatment system capable of breaking down and disposing of the wastewater and its characteristics produced by a McDonald’s restaurant.
  
• Obtain required permits.
  
• Meet budget constraints and stringent time deadlines in order to meet the scheduled grand opening.
  
• Provide a long-term performance warranty for the treatment system.
  
• Provide ongoing monitoring and maintenance.
  

The NCS Solution:

As always, the first step NCS takes in designing any system is to gain an understanding of actual hydraulic flows and wastewater characteristics (BOD, TSS and FOG) produced by a restaurant of this type. Careful review of the NCS monitoring data base that consist of our previously installed McDonald’s restaurants and other similar facilities is the key to correctly sizing the system.

Also the restaurant will be attached to a 24-hour Shell gas station/Convenience store, resulting in considerably more blackwater produced than in a typical free standing McDonald’s. The increased blackwater flow needs to be accounted for to correctly size the entire system.

Design:

• Capacity of 3500 gal/day average flow of commingle wastewater flows.
  
• 30 Nibbler pods capable of digesting 24.3 lbs/day BOD5.
  
• 7,000 square foot raised disposal bed based on a 0.50 gal/ft2/day hydraulic loading rate.
  
• Meeting Additional Client Requirements:
  
• NCS succeeded at meeting all budget constraints and time deadlines. The restaurant opened on time.
  
• NCS provided our standard 30-year performance warranty that Nibbler effluent will meet design discharge standards.
  
• Ongoing monitoring and maintenance provided by Milan Engineered Systems (Mt. Pleasant, MI) an NCS distributor.
  

Soil Loading Rates:

In the State of Michigan the soil loading rates (gal/ft2 /day ) for residential strength wastewater are higher than the loading rates imposed for restaurant strength wastewater. The Nibbler system reduces the waste strength of restaurant effluent at or below residential levels prior to disposal. The Midland County Health Department recognized the Nibbler® effluent as residential strength wastewater and allowed NCS to size the drainfield based on residential discharge standards.

Results:

NCS was able to increase the soil loading rate from 0.25 to 0.50 (gal/ft2/day), resulting in a size reduction of the drainfield from 14,000 square feet to 7,000 square feet.

Installation Challenges:

NCS would normally place all grease traps and septic tanks next to the building and separate the greywater and blackwater flows. To avoid the risk of having building footings cave in due to high ground water, NCS designed the system to commingle flows into one primary tank set 15 feet away from the building. Commingled effluent flowed into a smaller pump tank located in an adjacent landscaped area.

To set the tanks, a crane and an experienced excavator operator were necessary to excavate to a 9-foot depth. This had to be done quickly to prevent the side walls from caving in and the hole filling up with water. NCS brought in one of our own experienced superintendents from Washington State to supervise. Rohde Brothers Excavating located in Saginaw, Michigan provided the equipment and operators.

Effluent was then pumped to the surge and Nibbler tanks located in an area where the tanks were set above the water table. This eliminated the risk of ground water infiltration.