Tag Archives: Rest areas

Investigating Wastewater Reuse at Rest Areas and Truck Stations

Researchers have provided MnDOT with a comprehensive and practical evaluation of what the agency would need to do to develop wastewater reuse systems for its truck stations and rest areas. Two sites will install the research project’s recommended systems soon. 


Despite Minnesota’s abundance of water resources, 75 percent of the state’s water comes from aquifers at increasingly unsustainable rates. The recycling of wastewater for other uses would allow potable groundwater aquifers to be used more conservatively. Gov. Tim Walz and former Gov. Mark Dayton issued executive orders directing state agencies to make efforts to save energy and water. Since every MnDOT building uses water, the potential for substantial water reuse exists.

MnDOT sought to learn the potential for on-site wastewater reuse as well as the barriers to implementing, operating and maintaining water reuse systems. Developing a system of water recycling at MnDOT facilities could create sustainable water resources for toilet flushing and vehicle washing.

“The great success of this project arises from its close examination and evaluation of all aspects of industrial wastewater reuse in Minnesota, from regulation to the practical choice of technology MnDOT will be able to sustain into the future,” said Sara Heger, research engineer, Water Resources Center, University of Minnesota.

To that end, MnDOT initiated this research project to evaluate when reuse would make sense from a regulatory, environmental, economic and management perspective at more than 50 rest areas and 137 truck-washing stations and storage facilities.  

What Was Our Goal?

The objective of this project was to investigate and evaluate the potential for wastewater reuse within MnDOT. As part of the project, researchers would identify regulatory challenges, properties of wastewater streams, contaminants that would be difficult to remove or manage, potential treatment technologies and the MnDOT processes that would be suitable candidates for wastewater reuse. In addition, researchers intended to examine the possibility of recapturing salt-laden wastewater for further use in winter road maintenance.

What Did We Do?

The project’s work progressed in three phases:

  • Review of current wastewater reuse policies and regulations in Minnesota, wastewater reuse programs in other states, as well as international guidelines for water reuse. Researchers reviewed case studies about successful wastewater reuse systems implemented in Minnesota and examined potential regulatory barriers to wastewater reuse implementation.
  • Sampling and data collection from 11 MnDOT truck-washing facilities to determine common contaminants. Samples were taken year-round from an equal number of facilities with holding tanks and from those served by city sewer systems. Researcher collected 37 winter samples. In addition, a nonwinter sample was collected from each site to compare the characteristics of winter versus nonwinter samples.
A MnDOT maintenance worker and a University of Minnesota employee take wastewater samples from a waste trap at a MnDOT truck-washing facility.
At truck facilities connected to city sewers, researchers took wastewater samples from flammable waste traps while trucks were washed.
  • Evaluation of existing wastewater treatment technologies to identify those meeting MnDOT’s needs. Researchers investigated methods that could most effectively remove the identified contaminants from the wastewater while allowing chlorides to remain for brine production. Researchers also determined cost estimates over an assumed 25-year life span.

What Did We Learn?

Policies and regulation. Minnesota’s current state and federal regulatory framework addressing wastewater reuse is dispersed over multiple agencies, and rules can be contradictory. Currently at least four agencies are involved in wastewater regulation. Wastewater reuse systems require a variance and in some cases additional permits from local agencies. Researchers reported that the regulatory framework for water reuse in Minnesota needs to be simplified and streamlined to create a more effective permitting process.

Researchers noted that California has been a pioneer in water reuse since 1929. Florida is a national leader, recycling more than 727 million gallons per day, while Arizona developed effective water reuse regulations in 1972 and has been a regulatory model for Texas, New Mexico and Montana. Investigators suggested that Minnesota could adopt water use standards modeled on Arizona’s as the state clarifies its regulatory framework.

In addition, researchers reviewed four case studies in which wastewater reuse systems were successfully implemented.

Wastewater sample data. Researchers tested samples for volatile organic compounds, metals, fecal coliform, mercury, suspended solids, biochemical oxygen demand (BOD) and chlorides. They found excessive levels of only one chemical, ethylene dichloride, which is commonly used as a solvent; MnDOT could reduce its use of it. Across all samples, the critical contaminants to be removed for water reuse were organics (BODs) and suspended solids. Excessive chlorides were not considered a contaminant since chloride-rich water could be reused as brine in winter road maintenance operations.

“This innovative study’s findings will result in the implementation of wastewater reuse technology at two MnDOT sites. The project promises to be a continuing success,” said Neile Reider, administrative engineer, MnDOT Office of Maintenance.

Recommended technology. Researchers recommended that MnDOT use either a recirculating sand filter or a membrane bioreactor to treat wastewater. An economic evaluation comparing long-term costs of the two technologies indicated that the membrane bioreactor is the most economical system for MnDOT.

What’s Next?

A pilot implementation is planned for the Granite Falls, Minnesota truck station, a facility that is already plumbed to separate and collect washdown water. Evaluation of the system’s treatment effectiveness and maintenance requirements will inform the broader scale implementation of wastewater reuse systems for MnDOT.

This post pertains to Report 2019-22, “Investigating Wastewater Reuse at MnDOT Truck Stations,” published May 2019. Visit the MnDOT project page for more information.

New Project: Re-Using Water at Safety Rest Areas and Truck Stations

Water is being drawn out of the state’s aquifers faster than it is being replenished, so public agencies like MnDOT are increasingly interested in figuring out how to reduce water usage.

A two-year research project underway at MnDOT is investigating how the agency can re-use wastewater at its safety rest areas and truck-washing stations. In addition to preserving groundwater, MnDOT hopes to reduce utility and septic system costs.

MnDOT owns and operates over 1,000 buildings, including 68 safety rest areas, 137 truck stations, 18 regional/headquarters maintenance sites and 15 weigh stations and truck scales.

These facilities either discharge their wastewater to a subsurface sewage treatment system or a wastewater treatment plant.

Truck station with vehicles in parking lot
Maplewood Bridge Truck Station

Researchers from the University Of Minnesota’s Onsite Sewage Treatment Program have been hired to investigate the potential avenues for wastewater re-use at MnDOT. They will consider when re-use makes sense from a regulatory, environmental, economic and management perspective; recommend the most appropriate applications for reuse and identify any challenges with implementation.

Potential benefits include:

  • Preserve ground and drinking water for potable drinking.
  • Reduced life-cycle costs in areas where low-producing wells could meet drinking water needs while reused wastewater could be used for toilet flushing and equipment wash-down.
  • In areas with municipal water, lower water utility costs.
  • Increased longevity of septic systems due to decreased loads.

As the state, counties, or cities construct new facilities or upgrade existing ones, this research will provide insight into what options are readily available to reduce water consumption and improve water efficiency. If these types of reuse systems are demonstrated by MnDOT, then they could lead to usage by other properties across Minnesota.

Watch for new developments on this project.  Other Minnesota research can be found at MnDOT.gov/research.

Parking availability system takes aim at truck driver fatigue

MnDOT, in partnership with the Federal Highway Administration, is test-deploying a high-tech system to help combat drowsy driving and keep truck drivers in compliance with federal hours-of-service regulations.

Developed by researchers at the University of Minnesota, the prototype system lets  drivers know when parking spaces are available at rest stops ahead. It has been deployed at several locations along the heavily traveled I-94 corridor between Minneapolis and St. Cloud.

From today’s MnDOT news release:

ST. PAUL, Minn. – New technology along the I-94 corridor west and northwest of the Twin Cities is helping truckers find safe places to park. Three Minnesota Department of Transportation rest areas are now equipped with automated truck stop management systems that tell truck drivers when parking spaces are available.

The technology will improve safety, lead to better trip and operations management by drivers and carriers and help MnDOT and private truck stop owners manage their facilities more effectively, according to John Tompkins, MnDOT project manager.

“So far, the results have been positive. We’ve had 95 percent accuracy in determining the availability of spaces,” he said.

Federal hours of service rules require truck drivers to stop and rest after 11 hours of driving. Tompkins said if drivers continue to drive beyond 11 hours, they could become fatigued and be forced to park in unsafe locations such as freeway ramps. They could also face legal penalties.

The problem of truck driver fatigue recently took the national spotlight when an allegedly drowsy driver slammed his semitrailer into a limousine carrying actor-comedian Tracy Morgan and six others. One passenger died in the crash.

The parking availability project is led by MnDOT Freight Project Manager John Tompkins and University of Minnesota professor Nikolaos Papanikolopoulos. MnDOT Research Services & Library produced the video above, which demonstrates the system in action. You can learn more about the project on the Center for Transportation Studies website.

Research Drives Change At Rest Stops

In an effort to encourage more use of safety rest areas and reduce drowsy driving, the Minnesota Department of Transportation is bolstering amenities and plans to install new signage at select rest areas across the state.

Drowsy driving is conservatively estimated to cause at least 1,550 deaths nationwide each year and $12.5 billion in monetary damage.

Motorists would stop more frequently at rest areas if they knew what rest areas offered, according to market research completed in 2009.

MnDOT will design and install highway symbol signs to advertise the amenities at 13 rest areas in a pilot project funded by MnDOT’s Transportation Research Implementation Group.

“We are using this as a way to entice drivers to take a break, pull over and refresh before returning to the road,” said Robert Williams, MnDOT Safety Rest Area Program Manager and the project proponent.

Rest areas in Brainerd and Cass Lake, Minn., can now offer a tourism-related gift shop, thanks to a change in state law.
Rest areas in Brainerd and Cass Lake, Minn., can now offer a tourism-related gift shop, thanks to a change in law.

Amenities differ greatly between rest areas within the state, as well as across the country; this depends on when they were built and whether they are located on an interstate, state highway or toll road.

Older, smaller rest areas may only have a bathroom and picnic area, while newer facilities often have features such as children’s play areas, staffed travel counters and dog runs.

In the future, the state may consider new amenities such as gift shops, adult exercise equipment to rejuvenate motorists, electrical vehicle charging stations and perhaps even electrification stations to allow truck drivers to power their TV or refrigerator without idling their vehicle.

Research has found that as the spacing of rest areas increases beyond 30 miles, the number of drowsy driving crashes goes up exponentially, Williams said.

Each sign will advertise up to six amenities.
Each sign will advertise up to six amenities.

Proposed Signage

Symbols on each sign will identify up to six amenities, such as in the example above, which depicts an assisted restroom, gift shop, ticket sales, EV charging stations, childrens’ playlot and adult exercise equipment.

MnDOT will evaluate the pilot project to determine if the symbol signs are effective in communicating to travelers the amenities offered at individual rest areas and if the signs were a factor that encouraged them to stop.

If the two-year project goes well, the state may add similar signs to the remaining 39 Class I safety rest areas (those rest areas equipped with flush toilets).

Some of the signs will require a request to FHWA for experimentation.  The intent is to install the signs in the summer of 2015 at rest areas on northbound I-35, eastbound I-94, as well as at the Brainerd Lakes Area Welcome Center on Hwy. 371.

Rest Area Offerings Increase

Although travelers and state DOTs would often like to introduce new amenities, state and federal laws limit what states can offer.

Toll roads and highways built before 1960 (the Interstate era), mostly in the East Coast or Chicago area, have fewer federal restrictions than rest areas in Minnesota and may feature restaurants or convenience stores.

Changes to Minnesota state law in 2005 and recent changes to federal law in MAP-21 now allow limited commercial activities, such as tourism-related gift shops and ticket sales at rest areas. MnDOT and its partners have taken advantage of some of these changes at its visitor centers in Brainerd/Baxter and Cass Lake.

In addition, the state is exploring the concept of using rest areas as transit transfer facilities, where long-distance bus carriers and regional transit lines can exchange passengers.

These transit hubs would shorten travel times for long-distance travelers and allow the rest areas to serve multiple functions while providing a comfortable waiting area for passengers.

Rest areas
Pilot locations are circled.