MN Municipal Resource Guide Final

MINNESOTA MUNICIPAL ENGINEERING RESOURCE GUIDE

FOR PUBLIC OFFICIALS & MUNICIPAL STAFF

MUNICIPAL ENGINEERING RESOURCE GUIDE

WSB is pleased to provide you with our Minnesota Municipal Engineering Resource Guide. As a leader in civil engineering, planning, environmental and technology services for government agencies, we are committed to providing services that are transparent and understandable for staff and elected officials. Together, we can shape the world we live in.

Our industry frequently changes with new regulations and environmental concerns, and is full of acronyms. With this guide, we explain some of the issues that are most commonly addressed at the city council level. We hope it will be a resource for you and create opportunities for conversation that will produce a better understanding of the challenges you may face on a regular basis.

Through WSB University, our innovative learning initiative, we have developed a course that will allow for a question and answer session to explore these topics in greater detail.

We invite you to explore this resource when you’re tasked with making engineering-related decisions.

Sincerely,

BRET WEISS, PE PRESIDENT/CEO

Firm Overview

Forge Ahead.

WSB is a design and consulting firm specializing in engineering, community planning, environmental, and construction services. Our dedicated staff improves the way people engage with communities, transportation, infrastructure, energy and our environment. We offer services in a wide range of complementary areas that seamlessly integrate planning, design and implementation. wsbeng.com

WE SHARE A VISION TO CONNECT YOUR DREAMS FOR TOMORROW TO THE NEEDS OF TODAY — THE FUTURE IS OURS FOR THE MAKING.

A tool for you.

Public officials and city staff frequently encounter technical engineering issues that can be complicated by state statutes, agency regulations and design standards. As a policy maker or implementer, the complexity of potential challenges can be daunting, especially without a common starting point. Our Municipal Resource Guide is intended to serve as a quick reference manual on technical and engineering issues that cities and communities often encounter. We have served public agencies for over two decades and have prepared this guide as a reference and primer for all public officials. To start, find your topic in the adjoining table of contents.

This guide contains general information and is not intended as a substitute for specific recommendations. Your professional staff knows more about your community’s needs and can provide specific recommendations. Keep in mind that guidelines and regulations change and may be different from when this book was

Transportation Systems

HOW ARE ROADS CLASSIFIED?

HOW ARE ROADWAYS DESIGNED?

The design of a roadway affects its safety and capacity and is governed by uniform standards.

• Traffic lanes are generally 11 or 12 feet wide.

• Turn lanes are often used when a side street or driveway access poses a safety concern.

• Other roadway elements include parking areas, shoulders for disabled vehicles, bicycle lanes, and designated transit lanes or pullouts.

There are four primary roadway categories. The higher a roadway’s functional classification, the more important the roadway is for moving more vehicles at a higher rate of speed. Roadways are classified as principal arterials, minor arterials, collectors and local roads.

Principal arterials can be freeways or expressways, such as interstates, trunk (state) highways, or U.S. highways. These roadways have the highest posted speeds, the least amount of direct access and accommodate the most traffic.

Collector roadways connect to minor arterials. They generally link commercial/industrial areas or a large concentration of residential areas to minor arterial roadways. Access is more frequent compared to minor arterials, and speed limits are lower (30-45 mph). They are usually managed by a county or city.

Minor arterial roadways can be expressways, four-lane roadways or two-lane roadways. They are designed to move traffic and generally have speed limits of 40-55 mph. Access spacing is more frequent than on principal arterials, but less than collector or local roadways. Minor arterials are usually trunk (state) or county highways.

Local roads provide direct driveway access to homes and businesses. Access is frequent, speeds are low and the roadways are almost always two lanes. Cities manage local roadways.

WHO IS RESPONSIBLE FOR ROADS WITHIN THE CITY?

The responsibility for constructing and maintaining city roads falls under one of these jurisdictions:

• STATE - Interstates and trunk highways

• COUNTY - Most of the minor arterials and some of the collector roadways within the city

• CITY OR TOWNSHIP - Any public roadways that are not under the jurisdiction of the state or county. These are generally residential streets and some collector roadways

• PRIVATE - Roads constructed and maintained by adjacent residents or businesses

Although the city does not have direct responsibility for state and county roads within their boundaries, the city is usually involved in the planning, design, construction, and partial financing of these roads because of the impact on residents and other infrastructure.

HOW ARE SPEED LIMITS DETERMINED?

Speed limits are regulated by Minnesota Statute 169.14. Statutory speed limits are:

• 10 mph on alleys

THE MOVE TO “COMPLETE STREETS”

Non-vehicular modes of transportation are increasingly being integrated into today’s street designs. “Complete Streets” simply means designing the roadway corridor to accommodate alternate modes of transportation:

• TRANSIT - Rail and bus transit are usually planned and administered at a regional level (e.g., Metro Transit, Minnesota Valley Transit Authority, Southwest Transit). The routes are accommodated on the local roadway network and sometimes supported by municipally administered local transit networks.

Without maintenace, a road will only last about 20 years.

• 25 mph on residential roadways only if specifically adopted and signed by the local road authority

• 30 mph on streets in urban districts* or in rural residential districts* (no sign required)

• 55 mph on all other roads (except expressways and interstates)

Age of Pavement (years)

The Commissioner of Transportation has the authority to set speed limits if the statutory speed limits are not appropriate for a roadway. A city can request the Commissioner to set new speed limits. The Minnesota Department of Transportation (MnDOT) will then evaluate the roadway and recommend an appropriate speed based on a variety of factors. Speed limit could increase or decrease based on the results of the study and geometry of the roadway.

*As defined in the statute

• BICYCLE - Studies have shown that bicycle facilities are more frequently used if they connect to or are part of a larger network, connect to transit facilities, or access bicycle-friendly destinations or developments.

• PEDESTRIANS - Accommodations for pedestrians is the general practice along nearly all roadways, no matter how many users are anticipated. In addition, the Americans with Disabilities Act (ADA) requires that accommodations be made for disabled users on all public facilities.

As the speed allowed on the road increases, the number of exits and entrances to the road decreases.

Traffic Signals / Signage

WHY ARE THERE SO MANY SIGNS AND STRIPES?

Regulatory and warning signs are uniform nationwide.

• The location of signs with respect to turn lanes, intersections, and changes to lane configurations is also governed by the Minnesota Manual of Uniform Traffic Control Devices (MMUTCD).

• Informational signs, such as street names or places of interest, are at the discretion of the jurisdictional agency and its engineer.

• Striping along the roadway is uniformly placed (in accordance with the MMUTCD) to help direct traffic and improve safety.

CAN WE PUT IN A STOP SIGN TO SLOW TRAFFIC?

Stop signs have not been proven successful for slowing traffic. Many drivers operate by “feel”, if a stop sign is in an unwarranted location, drivers might not see it, resulting in an unsafe situation. Without constant enforcement, the typical driver may slow down at the stop sign, but compensates for the inconvenience by traveling faster between stop signs. Intersection controls such as stop signs are installed based on meeting specific criteria (called “warrants”), such as higher traffic volumes, accident history and pedestrian volume. A stop sign installed at a location where it is not warranted can often create a less safe environment.

WHAT CAN WE DO TO SLOW DOWN TRAFFIC?

Many communities are looking for ways to improve safety by slowing vehicle traffic through their streets. Called “traffic calming,” some of these measures are quite effective, but others are not.

EFFECTIVE METHODS OF TRAFFIC CALMING

• Radar speed signs

• Narrowing roadways

INEFFECTIVE METHODS OF TRAFFIC CALMING

• Additional or embellished stop signs

• Speed bumps

WHAT KIND OF INTERSECTION CONTROL DO I NEED?

Intersection controls such as stop signs, traffic signals, roundabouts and grade separations are selected based on specific criteria called “warrants.” Warrants are determined during an engineering study of the intersection. When all forms of control are considered, the study is called an Intersection Control Evaluation (ICE). When a signal is the only type of control being considered, the study is called a Signal Justification Report (SJR). Information gathered during the study includes:

• Intersection traffic volumes and turns

• Pedestrian counts and directions

• Speed and gap studies

• Crash history

• Intersection delay studies

A traffic signal usually cannot be installed unless it meets the warrant criteria and helps improve intersection safety and operations.

WHY BUILD ROUNDABOUTS?

Roundabouts are an increasingly common type of intersection control that can accommodate high vehicle volume. An engineering study is usually performed to determine if a roundabout is the appropriate control for the intersection. Roundabouts generally have a single circulating lane for smaller volumes and two circulating lanes for higher volumes. Roundabouts have been proven to be significantly safer than signals (70 percent reduction in injury crashes, 90 percent reduction in fatal crashes) due to the low entering speeds (15-20 mph). Roundabouts are still relatively new and often generate a stronger public reaction than signals. Studies have repeatedly shown, however, that public opinion is strongly favorable after installation.

Streets

WHAT ARE THE COMPONENTS OF A TYPICAL ROADWAY?

Building or maintaining a roadway—especially in an urban environment—usually involves much more than just the road. Some of the elements that need to be planned for and designed include:

• Curb or no curb

• Parking and lighting

• Sidewalks and trails

• Private utilities

• Landscaping and rain gardens

• Right-of-way management

HOW WIDE SHOULD THE STREET AND RIGHT OF WAY BE?

Street and right-of-way widths can vary based on a wide range of factors, including, traffic volumes, vehicle types, accommodations for alternate modes of transportation (transit, bicycles, pedestrians), turn lanes, parking, stormwater facilities, and city or private utilities. A typical cross-section of a road is shown in the figure on the facing page. While general guidelines are useful for planning, widths should be determined based on the specific needs of each roadway and corridor.

WHY CAN’T WE PARK ON EVERY STREET?

Many streets are paved beyond the minimum needs for the through and turn lanes. Often this width is minimal (about two feet). However, on high-speed roadways or roadways with only one through lane, you should consider a shoulder wide enough to accommodate a disabled vehicle. General shoulder widths are 8-10 feet. Many cities also allow additional width (usually 8 feet) for on-street parking, but this is usually a feature of a low-speed, residential environment, as parked vehicles reduce the driver’s field of vision.

WHY DO WE NEED BOULEVARDS?

The area between the curb and the sidewalk or trail is commonly called the boulevard. Some urban streets are built with sidewalks immediately behind the curb, eliminating the boulevard. However, there are many reasons to establish a boulevard, such as providing space for roadway signs, roadway or pedestrian lighting, snow storage, and a buffer between motorists and pedestrians or bicyclists.

WHAT ABOUT ADA REQUIREMENTS?

The Americans with Disabilities Act (ADA) requires that all public facilities meet certain design standards to accommodate users with disabilities. An ADA Transition Plan is required of cities, this involves inventorying existing facilities and planning for conversion:

• Transitions between sidewalk and road surface at crossings must conform to certain slopes and surface treatments.

• There are requirements for longitudinal slopes of trails and sidewalks, as well as cross-slopes.

• Traffic signals must conform to the ADA standards in regard to height of crosswalk push buttons and video/audio warnings.

• All new facilities must comply with these requirements. Roads built prior to enactment are largely exempt, but cities must have a plan for transitioning non-compliant roadways.

WHAT IS A TYPICAL STREET MAINTENANCE SCHEDULE?

Gravel roadways require regular grading in the summer months and resurfacing every 1-3 years. Some communities apply calcium chloride to reduce dust and minimize grading.

Asphalt roadways require surface repair such as pothole patching, crack filling, and sometimes larger patching on an as-needed basis. Many cities have a crack-filling program that’s typically completed every seven years to prevent water from saturating the road base which helps extend the life of the street.

Each city typically has its own snow and ice control policies regarding how much snow needs to fall before plowing, when plows are sent out, and how much sand or salt to apply. Many cities have reduced or eliminated sand for ice control, since it can wash into storm drainage systems, wetlands and ponds.

WHY START A PAVEMENT MANAGEMENT SYSTEM?

Of all the public infrastructure, streets tend to wear out first. Maintenance can extend their life and rehabilitation projects at the right time can avoid very expensive projects that require a total reconstruction of the street. Having a management plan or system is the first step to taking care of your streets as well as other important infrastructure. A Pavement Management System is a systematic method of inspecting and rating the condition of your pavement. Done properly, it can maximize the value and life expectancy of your roadways and help you budget resources.

Funding and Financing

HOW DO WE PAY FOR STREET MAINTENANCE AND CONSTRUCTION?

Cities in Minnesota with a population over 5,000 are eligible for state aid funding. The system works like this:

• Every year a portion of the state’s gas tax revenues (currently 9 percent) are distributed to each eligible city. Fifty percent of the allocation is based on the city’s population compared to the population of all other state aid cities.

• The remaining 50 percent is distributed based on the cost to construct roadways to state aid standards.

WHICH STREETS QUALIFY FOR STATE AID?

State aid streets are usually “collector roadways” that carry higher traffic loads and connect to major roadways or points of interest.

• State aid cities can designate up to 20 percent of their total road mileage as state aid streets. This mileage is reported annually by completing a “certification of mileage.”

• Construction needs are determined by assessing the existing and proposed roadway characteristics of each state aid street.

HOW CAN STATE AID FUNDS BE SPENT?

Cities can use state aid funds to pay for roadway construction and maintenance to state aid roadways or for the city’s share on county or state highways.

• With each apportionment, the city also receives funds for general maintenance

• Any remaining funds can be spent on roadway improvement projects

• To use state aid funds, designs must meet specific standards and be approved by MnDOT before construction

HOW DO WE BUILD AND MAINTAIN OUR INFRASTRUCTURE?

In general, the useful life of most city infrastructure is 15 years or more. It can be extremely expensive to build and most construction is funded with non-operational sources. Planning periods for any new construction are long and construction itself can be lengthy and disruptive to the community. The end result may be satisfying, but it usually comes with ongoing maintenance costs, as well.

CONSTRUCTION: THE IMPORTANCE OF CAPITAL IMPROVEMENT PROGRAMS (CIPS)

Most communities rely on CIPs to help them identify, prioritize and plan for the orderly replacement of their capital assets. CIPs have many benefits that make them indispensable, even for communities with relatively limited assets:

• You can coordinate multiple projects at all levels of your community and government

• Funding for required maintenance of infrastructure, such as maintenance and cleaning of stormwater ponds, can be identified and programed

• You can plan for economic development in an efficient and orderly manner

• Civic participation is improved as your community members can easily see your goals and plans

• Projects are prioritized and finances are easily monitored

WHAT ARE MN CHAPTER 429 SPECIAL ASSESSMENTS?

Most cities use special assessments to fund at least a portion of roadway improvement projects:

• A special assessment is a fee levied against properties for a public improvement that benefits the owners of the properties.

• Cities usually establish a policy for calculating special assessment amounts, based on frontage of the lot, the area or the individual household unit.

PROJECT INITIATION

By petition or council vote.

1 2 3 4 5 6 7 8 THE SPECIAL ASSESSMENT PROCESS

FEASIBILITY REPORT

Includes: when the project is needed; funds to pay the city’s share; cost estimates; whether the improvement is cost effective. Also includes estimate of assessment amount and method for calculation.

IMPROVEMENT HEARING

City council must discuss a specific improvement before ordering it. Notice of the hearing must be published in the official newspaper and mailed to all affected property owners.

ORDER IMPROVEMENTS

Within six months of the improvement hearing, the council can pass a resolution to order improvements.

CONSTRUCTION PLANS AND BIDDING

Plans and specifications are prepared and put out for competitive bidding.

ASSESSMENT HEARING

Allows property owners to express concerns about the assessment. Held following specific notice—before or after project is complete.

ADOPT ASSESSMENT ROLL

Council must adopt specific assessments by passing a resolution that typically includes an interest rate plus payment timelines.

CHALLENGING SPECIAL ASSESSMENTS

Property owners can object to assessments at the hearing but must file a District Court appeal within 30 days. They must provide evidence that the assessment fee total does not meet or exceed the benefit to the property. Concerns can be addressed in various ways; a ruling by a judge is the last resort.

Funding and Financing, cont.

LONG-TERM MAINTENANCE: THE IMPORTANCE OF ASSET MANAGEMENT SYSTEMS (AMS)

An AMS is a system for managing and maintaining your infrastructure. It allows you to track asset performance, maintenance costs and replacement costs over time. Many cities, for example, track their pavement and utility assets to schedule maintenance and plan future replacement.

• LIFE CYCLE TRACKING – Cities and counties can use an AMS to analyze the entire life cycle cost of an asset. By taking a life-cycle approach, organizations can make proactive decisions that improve service quality and reduce costs.

• COMMUNITY ENGAGEMENT – An AMS helps engage residents by allowing them to use their cell phones to report issues, which helps streamline operations, speed response times and keep residents updated on progress.

• A CHANGING ENVIRONMENT – Recent developments have made adopting an AMS even more important:

• Staffing levels have declined

• Infrastructure across the U.S. has deteriorated and limited funding has made maintenance more difficult

• A better-informed public demands higher levels of service

• Government standards are changing

WHY IS PAVEMENT MANAGEMENT SO IMPORTANT?

A community’s streets and roads are some of their most valuable and expensive assets. A Pavement Management System helps communities maximize the life of their roadways while minimizing costs. At the heart of any PMS are technical evaluations that allow cities to:

• Set expectations

• Develop goals

• Measure effectiveness

• Set CIP budgets

TWO BASIC WAYS TO FINANCE INFRASTRUCTURE

PAY-AS-YOU-GO (CASH)

For budgetary or replacement assets such as computers, vehicles and minor maintenance, many communities simply pay project costs with cash from either current revenues or reserve funds.

PAY-AS-YOU-USE (DEBT)

For large capital assets or those with a long useful life—such as buildings, structures, real estate and major asset improvements— it’s more common to issue debt and pay for project costs with bonding proceeds. The debt is then paid for by users over time.

CAN WE FIND FUNDING?

NON-LOCAL SOURCES OF REVENUE:

• Federal aid

• State aid

• Cooperative agreements

• Federal grants

LOCAL SOURCES OF REVENUE:

• General tax levies

• Special assessments

• Grants

• Development or redevelopment funds

• TIF/Tax abatements

NEW AND NON-TRADITIONAL SOURCES OF REVENUE:

• DEED grants

• TED grants

• Clean Water, Land & Legacy Amendment distributions

• The Flood Damage Reduction Grant Assistance Program

• MN Department of Natural Resources funds

• Franchise fees

• Stormwater utility fees

• Streetlight utility fees

Stormwater Runoff

WHY IS STORMWATER RUNOFF SO IMPORTANT?

The Federal Environmental Protection Agency (EPA) considers untreated stormwater a pollutant and has mandated that cities over a certain size obtain an NPDES MS4 permit to operate stormwater systems. The MS4 general permit is designed to reduce the amount of sediment and pollution that enters surface and ground water from stormwater systems.

HOW DO WE MEET STORMWATER REQUIREMENTS?

Communities use a variety of tools to help mitigate the effects of stormwater, including:

Building

Designing underground infiltration systems

Encouraging

Reusing water for landscaping and other purposes

WHAT IS A DESIGN STORM?

• “Design storms” are defined based on their probability of occurrence in a given year, based on Atlas 14 rainfall data.

• A 10-year event has a 10 percent chance of occurring and a 100-year event has a 1 percent chance.

• Cities use different design storms: a 100-year for flood control, a 5 to 10-year for local street storm sewer, a 6 month to 1-year for water quality, and generally a 2 to 5-year for stream protection.

• The use of different design storms is based on both economic and hydrologic factors. Flood protection for large, infrequent events is a public benefit that is worthwhile to minimize damage to properties. However, designing local streets for a 100-year event is cost prohibitive, so we live with transient street flooding for large rainfalls greater than a 5 or 10-year storm.

HOW DO WE PREVENT FLOODING?

Over the last three decades, intense precipitation and runoff events have become more common, making flood control an emerging concern. Flood control systems rely on the complex interaction among ponds, storm sewers, culverts, outlet structures, channels, levees, reservoirs, and other components to keep water away from roadways, buildings, and homes for a specific design event - usually the 100-year event in newer communities. Due to costs, most local governments opt for the 100-year design for flood control, although some frequently flooded cities have considered the feasibility of more robust flood control systems.

HOW DO WE MEET STORMWATER REGULATIONS?

In the 1980s, the EPA concluded that untreated stormwater runoff significantly degraded the quality of our public waters and began to regulate urban stormwater. The Minnesota Clean Water Land and Legacy Amendment aimed to protect and improve water quality. Water quality practices, known as Best Management Practices (BMPs), were developed for construction sites, urban, and agricultural land to protect public waters. When Minnesota’s public waters do not meet their designated quality levels, the Minnesota Pollution Control Agency (MPCA) develops a Total Maximum Daily Load (TMDL) for nutrients, biota, bacteria, turbidity, mercury and others to help restore the water quality. The MPCA, Watershed Districts and management organizations and cities all coordinate to administer water quality regulations.

The MPCA has made infiltration the centerpiece of their water quality protection strategy through the development of Minimum Impact Design Standards (MIDS). In general, if municipalities adopt MIDS, the state assumes that the municipality is protecting water quality to the maximum extent. Cities should be careful, however, how infiltration requirements get applied, since surface infiltration may require a lot of land, more frequent maintenance and success of the practice depends on having reasonably porous soils.

Typical Utility System

Water Supply

WHERE DOES OUR DRINKING WATER COME FROM?

The vast majority of Minnesota cities use groundwater pumped from wells, but some use surface water (lakes or rivers) as their water supply. The Minnesota Department of Natural Resources manages the use of groundwater.

HOW MUCH WATER DOES A TYPICAL CITY USE?

Typical water usage is:

• 75 - 100 gallons per person per day

• 200 - 300 gallons per person per day on peak days

Peak water use days typically occur during the summer when irrigation is prevalent.

Most cities use a variety of methods to help conserve this critical natural resource:

• Watering limits (e.g., odd/even), conservation rates (higher rates for higher usage) or seasonal rates

• Maintaining a fully metered system and performing annual water audits

• Locating and repairing leaks

• Managing water pressure to help reduce leakage

• Establishing water conservations goals

• Promote efficient landscaping and irrigation

HOW MUCH TREATMENT IS REQUIRED?

FLUORIDATION

• Helps prevent tooth decay

• Mandated by state law

CHLORINATION

• Helps prevent bacterial contamination

• Mandatory for surface water supplies

• Recommended for groundwater supplies

SURFACE WATER:

• Treatment of surface water sources is mandatory

• Softening of surface water is optional

OPTIONAL TREATMENT (GROUNDWATER):

• Iron and manganese removal, which is commonly used to eliminate staining, tastes and odors caused by these elements

• Softening to remove hardness

WHAT MAKES UP A CITY WATER SYSTEM?

A typical city water system includes:

• Wells that supply the water

• Water reservoirs and/or towers that store a reserve of water for peak day needs, fire-fighting and maintaining consistent water pressure

• Treatment plants that bring the water to desired or mandated levels

• Water distribution systems – the pipes, valves and hydrants that deliver water to users

WHO OPERATES AND MAINTAINS THE WATER SYSTEM?

Most cities have a public works or water utility department that operate and maintains the water system. Their responsibilities include:

• Daily checks and operational adjustments of wells, water towers and treatment plants

• Repair of water main breaks

• Semi-annual flushing of hydrants and exercising valves

• Periodic well maintenance and pump replacement

• Periodic repainting of water reservoirs and towers

HOW IS THE WATER SYSTEM PAID FOR?

Sources of revenue to construct, operate, and maintain water systems include:

• USER FEES – Nearly all Minnesota communities charge for water based on monthly, bi-monthly or quarterly water meter readings. Water user fees typically fund operation and maintenance of the system, as well as create the reserves necessary for replacing aging infrastructure.

• CITY WATER AVAILABILITY CHARGES (WAC) – Many communities require payment of a WAC when a new user connects to the system. WAC charge revenue helps fund construction and expansion of the water system including wells, towers and treatment plants.

• TRUNK CHARGES – Some growing communities require a trunk charge, typically paid at the time property is subdivided for new development. These charges help fund trunk system improvements (water towers, wells and larger water mains) needed for the new development areas.

• NEW WATERMAINS - Watermain construction for developing areas is typically financed by developers or industrial/commercial users.

Wastewater

WHAT IS WASTEWATER AND WHERE DOES IT COME FROM?

Wastewater is used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff or stormwater, and any sewer inflow or sewer infiltration. Types of wastewater include: domestic wastewater from households, municipal wastewater from communities (also called sewage) or industrial wastewater from industrial activities.

• It’s estimated that every resident of a community generates about 50 to 100 gallons of wastewater per day.

• Industrial wastewater is highly variable in volume and contaminants based on industry.

HOW IS WASTEWATER COLLECTED?

Wastewater is discharged to a collection system (also referred to as a sanitary sewer system). Each home or business has a small-diameter pipe called a service line. This line connects to the collection system — a pipe network that conveys wastewater to a treatment facility.

HOW ARE

WASTEWATER COLLECTION SYSTEMS

DESIGNED?

Typically, wastewater collection systems are designed for gravity flow, as this is the most reliable. Occasionally, it’s necessary to pump wastewater to a higher elevation via a lift or pumping station. The lift station includes a wet well to temporarily store wastewater and two or more motors to pump it to an elevation where the sewage returns to gravity flow. Two pumps are required in case one fails.

INFLOW AND INFILTRATION (I/I)

Inflow and infiltration is clean storm or groundwater that enters the sanitary sewer system through holes, breaks, joint or connection failures, illegally connected sump pumps, downspouts, footing drains, and storm sewer crossconnections.

• Most inflow comes from stormwater and most infiltration comes from groundwater

• Excessive inflow and infiltration can cause sewers to back up or even overload sewage treatment plants, which can reduce treatment time or bypass the treatment process all together during high rainfall

• Sanitary sewer overflows can pose a significant health and environmental challenge

How to reduce I&Is:

• Regular sewer system cleaning and maintenance

• Repairing broken or leaking service lines, manholes, and sewer mains.

• Upgrading sewer, pump station or plant capacity

• Construct facilities to treat excess flows

WHAT MAKES UP A CITY WASTEWATER COLLECTION AND TREATMENT SYSTEM?

A typical wastewater collection and treatment system includes:

• SERVICE LINES - Pipes from individual homes and businesses that carry wastewater to the collection system

• WASTEWATER COLLECTION SYSTEM - Pipe network that collects and conveys wastewater from the service lines to the wastewater treatment facility

• LIFT STATIONS - Pumping facilities that lift wastewater to a higher elevation

• WASTEWATER TREATMENT FACILITY - Stabilization pond system or mechanical plant that treats wastewater before discharging to a stream, river or lake. In the metro area, discharged wastewater goes to the Metropolitan Council interceptor sewer system for treatment in one of seven wastewater treatment facilities. Outside the metro area, cities operate their own facilities

WHO OPERATES AND MAINTAINS THE WASTEWATER COLLECTION AND TREATMENT SYSTEM?

Most cities have a sewer department, although most in the Twin Cities area do not have treatment facilities. Generally, cities have utility staff with appropriate licenses that manage both the water and sewer systems.

Duties include:

• Daily checks of lift stations

• Annual wet well cleaning and periodic maintenance of lift stations

• Daily operation of treatment facilities

• Jetting (high-pressure water), cleaning, and televising all collection system pipes on a 4 to 5-year cycle

• Minor repairs to the collection system

HOW ARE SEWER SYSTEMS PAID FOR?

Sources of revenue to construct, operate, and maintain water systems include:

• USER FEES - Nearly all Minnesota communities charge for sewer based on monthly, bi-monthly or quarterly meter readings. Sewer user fees typically fund operation and maintenance of the system, as well as create the reserves necessary for replacing aging sewer infrastructure.

• CITY SEWER AVAILABILITY CHARGES (SAC) - Many communities require payment of a SAC when a new user connects to the system. SAC revenues help fund construction and replacement of the sewer collection system and treatment plants.

• METROPOLITAN COUNCIL SAC CHARGE (TWIN CITIES METRO AREA ONLY) - This is required when a new user connects to the system. The city collects the charge and provides it to the Metropolitan Council. The revenue is used to construct and maintain the Metropolitan Council’s sewage collection system and wastewater treatment plants.

• TRUNK CHARGES - Some growing communities require a trunk charge, typically paid when the property is subdivided for new development. These funds are used to build trunk system improvements (lift stations and larger trunk sewer mains) needed to service the new developments.

• NEW SEWER MAINS - Sewer mains built to allow for growth or replace septic systems are typically financed by the respective property owners.

Environmental

MINNESOTA’S ENVIRONMENTAL POLICY ACT (MEPA)

Minnesota Rule 4410 requires environmental review for projects that meet a certain threshold. This includes projects like residential, commercial, industrial, some road projects and large sanitary sewer projects. Environmental review is accomplished through the development of an Environmental Assessment Worksheet (EAW), Environmental Impact Statement (EIS) or Alternative Urban Areawide Review (AUAR).

WHAT IS AN EAW?

An EAW is the most basic environmental review in Minnesota. Projects that trigger an EAW are required to evaluate environmental impacts. The analysis for an EAW includes evaluating a wide range of potential impacts such as wildlife, stormwater, infrastructure and traffic. An EAW determines if there are any environmental impacts that cannot be addressed through regulations or permitting and whether an Environmental Impact Statement is needed.

An EAW can take 3-6 months and includes a 30-day review period for agencies and the public to comment. The Responsible Government Unit (RGU) is required to issue the ruling on whether an EIS is necessary based on the results of the EAW.

WHAT IS AN EIS?

An EIS is more extensive and in-depth than an EAW. A project either triggers an EIS based on its own magnitude pursuant to Minnesota Rule or as the result of the EAW indicating an EIS is needed. The EIS evaluates the same potential environmental impacts as an EAW, but with more in-depth analysis. An EIS process can take 12-24 months.

WHAT IS AN AUAR?

An AUAR is a hybrid of an EAW and an EIS. It is a useful tool if a specific project has not been identified but a city wants to evaluate the environmental impacts of development over a larger area. This allows cities to plan for needed infrastructure and informs developers what sorts of environmental mitigation may be needed. An AUAR can take between 10-18 months. The result of an AUAR is a guide plan for the required mitigation items.

HOW WETLANDS WORK

and sediment

WANT TO KNOW THE QUALITY OF THE WETLANDS IN YOUR CITY?

Many cities have completed a wetland management plan that assesses wetland functions and values. This can aid in creating local policy and understanding the resources in the city.

WETLAND REGULATIONS

Wetlands are an important natural resource in the land of 10,000 lakes. They provide a variety of benefits including flood protection, open space, habitat for wildlife and water filtering. Several agencies regulate wetlands, including the U.S. Army Corps of Engineers, local watershed districts, the Department of Natural Resources and the Local Government Unit (LGU) for the Wetland Conservation Act (WCA).

If a project is proposed near a wetland, a delineation needs to be completed to determine the boundary. This is done by a certified wetland delineator or a scientist knowledgeable in wetland science.

WHAT IS THE PROCESS FOR DESIGNING NEAR A WETLAND?

1. AVOID – Projects must try to first avoid all wetland impacts.

2. MINIMIZE – If impacts are unavoidable, they must be minimized.

3. MITIGATE – If impacts cannot be avoided, replacement (or mitigation) for those impacts is needed. Permits are required from the permitting agencies.

Mitigation can be accomplished by purchasing wetland credits from the state’s wetland banking system or on site by restoring or creating new wetland. Wetland mitigation is generally required at a 2:1 ratio, but this can differ based on impacts and location.

Right-of-Way

WHAT IS RIGHT-OF-WAY?

Right-of-way is the interest the city, county or state have in a property defined as either fee title, an easement or prescriptive easement. Rights to use property may also be granted by a license or permit.

WHAT KINDS OF RIGHT-OF-WAY MAY BE ACQUIRED?

• FEE TITLE – All inclusive but subject to existing encumbrances.

• PERMANENT EASEMENT – For a specific use such as a roadway, drainage, utilities, trail, wall, pipeline, etc.

• TEMPORARY EASEMENT – To obtain working space for project construction - has a specific expiration date.

• ACCESS RIGHTS – To limit access, as in “access control”, or to obtain access rights to maintain a public improvement, such as a structure.

• AIR RIGHTS – Overpass

• UNDERGROUND RIGHTS – Tunnel

• OTHERS

WHEN SHOULD RIGHT-OF-WAY STAFF BE INCLUDED IN A PROJECT?

Early discussions are vital when scoping a project and aid in identifying potential challenges or improvements. Often, through a minor design change, impacts can be avoided. Additionally, early or advanced right-of-way acquisitions can improve project timing while also benefiting landowners.

WHAT PRINCIPLES ARE FOLLOWED FOR RIGHT OF WAY ACQUISITION?

Due to several federal and state legal rights that protect both landowners and the city, coordination with legal counsel is a necessary first step when right-of-way is involved. The Uniform Relocation Assistance and Real Property Acquisition Policy Act of 1970 are guidelines that are followed depending on funding sources involved in the project.

Acquisition

For right-of-way acquisition, coordination with city staff and the city’s legal counsel is a necessary first step. The 14th Amendment to the United States Constitution states that “No person shall... be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use without just compensation.”

Relocation

If a partial or total acquisition results in the displacement of a landowner or a tenant, relocation guidelines must be followed. Relocation benefit guidelines can vary based on funding sources. Contact the relevant state agency or a city engineer for more information.

GIS / Asset Management

WHAT IS GIS?

Geographic Information Systems (GIS) are computerized mapping systems for collecting, managing and analyzing data. By allowing overlay of various spatial layers, GIS helps you visualize information and better understand relationships between data.

HOW IS GIS USED BY CITIES?

Administrative staff often use GIS to help quickly access information. This helps them provide faster and more accurate answers to residents. GIS also helps save time by automating tasks such as generating mailing labels.

Planning and building officials often use GIS to review historic building information like aerial photography, code violations and detailed data from plan reviews. Having a single data repository can streamline operations and provide a permanent data warehouse for future reference.

Engineers and public works operators often use GIS to access detailed information about city infrastructure, such as as-built drawings. Because many assets are located throughout the city or county, staff can use mobile GIS solutions to access information they need in the field when they need it.

WHAT IS AN AMS?

An Asset Management System (AMS) allows you to track asset performance, maintenance costs and replacement costs over time. For example, many cities track their pavement and utility assets to help schedule maintenance and plan future replacement.

HOW DOES AMS ADD VALUE TO A CITY OR COUNTY?

Cities and counties can use an AMS to analyze the cost of the entire life-cycle of an asset, such as a road or sewer line. By taking an AMS-based life-cycle approach, an organization can make proactive decisions that increase the quality of service and reduce costs.

AMS allows local residents to participate with the city in maintaining their community. Residents are easily able to report issues in the community from their cell phones which streamlines city operations, reduces response times and allows residents to track their requests.

WHAT’S NEW FOR PUBLIC WORKS WORK ORDER MANAGEMENT?

Over the last few years, we have seen more cities move towards Work Order Management systems that link directly to their AMS. This allows cities to monitor the service provided to residents and track the time and resources spent maintaining infrastructure.

More cities are taking the next step by using Cartegraph YourGov® to provide residents direct access to work orders with smart phones. This allows residents to see how cities are responding to issues in real time. This same technology allows public works operators to use iPhones, iPads and Android devices to access the information they need more efficiently.

Bridges

WHAT LEGAL RESPONSIBILITIES DO BRIDGE OWNERS HAVE?

Every municipality that owns a bridge in Minnesota must appoint a bridge program administrator — a professional engineer with a bridge background. The bridge administrator is responsible for ensuring that bridges are inspected, load rated, and load posted in accordance with state and federal law.

WHAT DOES A BRIDGE SAFETY INSPECTION INVOLVE?

A bridge safety inspection is an evaluation of the physical condition of a bridge. It involves both visual and hands-on evaluation of all bridge components. The inspector looks for corrosion, deterioration, settlement, damage and scour. The results are detailed in a report based on each component and the overall condition is compiled in an online database. Bridges are required by law to be inspected either annually or biannually, depending on their type and condition. Underwater inspection may be required for bridges with components that are not visible during low water conditions.

HOW DO YOU KNOW WHEN IT IS TIME TO REPLACE A BRIDGE?

A Sufficiency Rating of 80 or less is required for federal repair funding and a rating of 50 of less is required for federal replacement funding.

Historically bridges were designed for 60-75 years of service life, with the decks replaced at about midlife (30 years). More recently, bridges are being designed for 75-100 years of service life with bridge decks replaced at midlife (40 years).

WHAT IS A BRIDGE LOAD RATING?

A bridge load rating is a calculation to determine the safe load carrying capacity of a bridge. This calculation is required when the bridge is constructed and when the condition or configuration of the bridge has changed. The results determine if a bridge should be load posted and whether it’s safe for special permit vehicles to cross.

MnDOT now requires a new load rating method for new and rehabilitated bridges. The new method is called Load and Resistance Factor Rating (LRFR), which replaces the Load Factor Rating (LFR) and Allowable Stress Rating (ASR) methodologies. The LRFR method uses a heavier truck live load (HL-93), which matches the current design truck. Existing bridges designed prior to 2010, that were not designed for the HL-93 truck, may have low load ratings (and possible require posting) if rated under the LRFR method. It is often recommended to limit the rehabilitation scope (no change in dead load) of older existing bridges to avoid the LRFR method and load posting.

Structures

WHAT RETAINING WALL TYPE IS BEST SUITED FOR A PARTICULAR SITE?

There are numerous types of retaining wall systems - each have cost, impact, strength, durability and aesthetic differences. In general, if utilities, groundwater, and excavation limits are not a concern the prefabricated modular block wall (PMBW) is a preferred and cost-effective wall type for walls under 8 feet in height. WSB has created a retaining wall applications data sheet for client use to help them determine the best wall type for certain applications.

HOW

DO I KNOW IF MY BUILDING STRUCTURE IS SAFE OR CAN BE MODIFIED FOR A NEW USE?

If building structural evaluation is desired, having the existing building plans greatly expedites the process of structural review. If these plans do not exist, an engineer will visit the site, review the structural condition and can perform a 3-D scan of the building - which for larger and more complex structures is a more efficient process than manually measuring. Based on the outcome of the assessment and structural analysis, we can answer your specific structural inquiry. Many times safety concerns arise from the discovery of cracks, corrosion, settlement and large deflections. Monitoring devices can be installed to document and track these defects in regard to safety and provide piece of mind to owners.

WHAT ARE NEW ADVANCES IN BRIDGE AND STRUCTURAL MANAGEMENT?

The future of structural design and management, including bridges, is BIM (Building Information Modeling). BIM is an intelligent 3D model-based process that gives engineering, architectural and construction professionals the insight and tools to more efficiently plan, design, construct, maintain and manage infrastructure.

WHAT ARE SOME METHODS OF RISK MANAGEMENT USED FOR STRUCTURAL PROJECTS?

Structural projects adjacent to existing structures should consider the use of vibration monitory and precondition/post-condition surveys to limit the potential liability for damage. For structural projects in more unique locations, additional geotechnical investigation (borings, test pits) should also be considered to limit construction related issues and change orders.

Project Design and Construction Administration

WHAT DOES A CONSTRUCTION INSPECTOR DO?

Construction inspectors provide a wide range of essential services:

• They address concerns from residents and business owners

• Analyze the safety of site conditions

• Provide real time communication about project progress and issue management

• Document the work as it progresses and assist with risk management through changing field conditions

• Review project costs, contractor workmanship schedules, and overall quality

• Their reporting and documentation is also used in claims avoidance situations if they arise

WHEN DO SURVEYORS GET INVOLVED?

Surveyors are typically involved in all phases of a municipal improvement project. Initially, they provide data collection for the preliminary and final design phases, which includes gathering topographic information, analyzing existing easements and public right-of-way to document existing site conditions.

During the construction phase, surveyors stake out the limits of construction, alignment and grade for sewer, water, street and other site work. Depending on their method of payment, surveyors can also measure material quantities in the field.

Once the construction project is completed, surveyors gather field data as-built drawings that help verify that the project was completed according to the construction documents.

WHY IS MATERIAL TESTING IMPORTANT?

Often, the success of a project comes down to the quality and consistency of materials used in the construction process. Material testing helps verify that the materials and construction methods selected meet the quality control requirements of the construction documents.

WHAT IS PAVEMENT FORENSICS?

Pavement forensics encompasses a variety of approaches to help assess pavement structure. For example, pavement coring can be used to extract a pavement sample and identify what exists under the visible top layer. This analysis gives a wealth of information, including width of the layers, signs of bonding or unbonding, and distresses not visible from the road surface.