Category: Engineering

The New Hampshire MS4 Stormwater Permit: What’s Next?

Image of a stormwater outfall area as body of water

For our friends in the MS4 communities, hopefully, you completed the Year 1 requirements to meet the June 30, 2019 deadline. This included, among other things, completion of a Stormwater Management Plan (SWMP), Illicit Discharge and Detection Elimination (IDDE) Plan, outfall ranking and prioritization for subsequent outfall investigations, construction site runoff control procedures, a schedule for catch basin cleaning, a schedule for street sweeping, written winter road maintenance procedures, distribute two targeted messages (depending on the community), and develop a Chloride Reduction Plan. So, what’s next?

MS4 communities must continue to work on/update the stormwater system mapping. This includes key elements and features of the stormwater conveyance system, structural Best Management Practices (BMPs), open channels, etc. 2003 MS4 communities have two years (until June 30, 2020) to complete the update of the stormwater system mapping. New MS4 communities as of the 2017 MS4 have 3 years (until June 30, 2021) in which to complete the mapping of their stormwater system. As part of this effort, the initial catchment delineations should be refined as well. Systematic investigation of problem catchments, or high-priority catchments if there are no problem catchments, is to be started. A written catchment investigation procedure must be developed by December 31, 2019.

The investigation of problem and high-priority outfalls starts with a field inspection during dry weather. If dry-weather flow is observed, then further screening is required to determine if there may potentially be illicit discharges present. This can be done using field test kits; however, screening for bacteria requires laboratory testing. The results of the screening will determine whether additional investigation is required to determine sources of illicit discharges. The outfall ranking and prioritization will also be updated accordingly.

Stormwater outfall concrete pipe with water draining out of itGood housekeeping procedures must be developed for permittee-owned facilities, including: develop inventory of all permittee-owned facilities; develop O&M procedures for municipal activities; develop O&M procedures to reduce/minimize/eliminate discharge of pollutants; develop and implement Stormwater Pollution Prevention Plan (SWPPP) for municipally-owned facilities such as maintenance garages, public works yards, salt sheds, transfer stations and other areas where pollutants are exposed to stormwater; and cover salt storage areas. Are you having fun yet?

Public Education and Outreach activities must be continued during Year 2. This involves distributing two targeted messages.

Permittees lucky enough to have discharges to waters with an approved Total Maximum Daily Load (TMDL) have additional activities to complete during Year 2 as well. Permittees subject to an approved TMDL for chlorides must begin implementation of their Chloride Reduction Plan. Permittees subject to an approved bacteria and pathogen TMDL must disseminate public education materials and work on implementation of their IDDE plan. Permittees subject to a phosphorus TMDL must have a legal analysis of their Lake Phosphorus Control Plan (LPCP) completed.

Permittees with discharges to impaired waters without an approved TMDL would be well advised to begin planning for future MS4 permit obligations as well. Impairments to waters without an approved TMDL include: nitrogen, phosphorus, bacteria or pathogens, chloride, total suspended solids, metals, and oil and grease. Did you know that leaf litter contributes phosphorus and nitrogen to stormwater runoff?

Did I mention that the Year 1 annual report must be completed and submitted by the EPA-extended date of September 30, 2019? The reporting period for Year 1 is from May 1, 2018 to June 30, 2019. The reporting period is from July 1 to June 30 for all subsequent years. The EPA has developed a template based on the 2017 MS4 permit that can be used for the annual report. The template can be found here.

The Hoyle, Tanner team of experts is available to assist you as needed with MS4 permit compliance. If you have questions, please contact Michael Trainque (mtrainque@hoyletanner.com) or Heidi Marshall (hmarshall@hoyletanner.com) at Hoyle, Tanner & Associates, Inc.

 

Additional information:

https://www.epa.gov/npdes-permits/new-hampshire-small-ms4-general-permit

https://www.epa.gov/npdes-permits/stormwater-tools-new-england#arr

Heat Safety: 4 Tips to Stay Safe on Construction Sites During Summer

Heat illness prevention graphic of construction worker

Summer is officially here, and although the warm weather brings promises of barbecues, beach days and the hum of AC, working in the summer heat is not something to be taken lightly. For construction laborers and other outdoor workers, the heat can drain your energy and be very dangerous if proper precautions aren’t taken.

According to the Bureau of Labor Statistics’ most recent data, in 2015 over 2,830 American workers suffered from a heat-related illness that required at least one day away from work. In order to prevent more injuries now and in the future, it is important to spread awareness in the workplace about how to stay safe while out and in intense summer conditions. By planning ahead and executing these simple safety measures, you will be happier, healthier and ready to enjoy all the fun that the summer heat has to offer.

Drink Water

Staying hydrated is the single most important thing you can do to prevent heat-related injury or illness. The Occupational Safety and Health Administration recommends drinking water every 15 to 20 minutes even if you are not thirsty. Additionally, anyone exposed to prolonged periods of sweating should balance out their electrolytes by drinking sports drinks such as Gatorade or Powerade. Keep in mind, though, that sports drinks are laden with food dye and sugars, so you can also boost your electrolytes by eating mineral-rich foods like bananas, nuts, yogurt, and dark green vegetables like kale. Coconut water is another good source of replenishing electrolytes. If you can’t carry snacks around, some say that adding a pinch of salt and a squeeze of lemon to your water can have a similar satisfying effect.

Be Cautious of Caffeine

Coffee is an essential part of the day for many Americans. However, all caffeine — whether it be coffee, tea or soda — can be dangerous on a hot summer day if you aren’t careful. This is because caffeine can be diuretic, meaning that it causes water loss in the body and dehydrates you more quickly. Whether or not caffeine is actually a diuretic has been debated over the past few years, but your reaction is also very subjective; someone who rarely drinks caffeine may feel its effects more than a daily consumer, especially on a hot day. Drinking water throughout the day should counter these effects, but be wary of drinking excessive amounts of caffeine, especially while on the job site.

Take Breaks

Do not be afraid to take breaks. No job is worth risking your health over. The heat can be draining, and it is important that you allow yourself the time you need to recuperate. When you do take breaks make sure you find some shade, drink at least 20 ounces of water and reapply sunscreen. For lunch, eat healthy and energizing foods. You will be surprised how much stronger you feel throughout the day.

Know the Symptoms

Excessive heat can lead to heat exhaustion and heat stroke. It is important that you are able to recognize these symptoms and know what to do if the situation arises.

Heat Exhaustion

Nausea, vomiting, headaches, weakness, confusion, dizziness, and cool, pale, moist or flushed skin can all be signs of heat exhaustion. If you or someone you know is experiencing any of these symptoms it is important that you immediately move them to a cooler location and start to loosen any tight or heavy clothing they are wearing. You need to lower the person’s body temperature by any means necessary. Some examples of how to do this include fanning them, spraying them down with cool water or resting wet towels on their skin. If the victim is conscious, start replenishing their fluids by having them drink water slowly (about 4 ounces every 15 minutes). Keep a careful eye on the person and watch for any changes in their condition. If they refuse care, begin to lose consciousness or start to vomit, call 911 or local emergency authorities immediately.

Heat Stroke

Signs of heat stroke include hot dry red skin, confusion, loss of consciousness or convulsions and seizures. Heat stroke is an extremely serious condition and can be fatal, so if you witness anybody experiencing any of these symptoms, call 911 immediately. While waiting for help to arrive, cool the person down as quickly as possible. If circumstance allows, immerse the person up to their neck in cold water. If that isn’t an option, spray the person down or apply ice packs or wet towels to their skin.

For more information on what to do when temperatures rise, download the free Red Cross Emergency App. The app also gives users the option to receive alerts for excessive heat watches, warnings and heat advisories.

We want this summer to be memorable for a lot of reasons, but overheating is not one of them. When working outdoors in hot weather, the most important things to remember are water, shade and rest. Anyone can be at risk for severe dehydration and heat exhaustion, but people who are not used to prolonged exposure to heat typically are at a higher risk of suffering an injury. As things start to heat up this summer, ease your way into your work, especially if you are a new employee. Listen to your body and take the necessary precautions to ensure that you are both safe and successful.

Now get out there and enjoy the sunshine!

 

 

Written by Grace Mulleavey

 

 

 

 

MS4 Regulations in New Hampshire Communities: How to Deal with Stormwater

Storm Drain Photo

Whew!! You got that Notice of Intent form submitted (hopefully) to EPA on or before October 1. Now what? Grab a cold one, sit back, relax? Wishful thinking. Now the real fun begins.

Stormwater Sampling For those communities that have not already done so, stormwater outfalls from the MS4 area must be located, mapped and assigned a unique identification number. Then an inspection and condition assessment must be done for each outfall. If you were an MS4 community subject to the 2003 permit, you would have (or at least should have) completed this. However, you are not finished. Mapping completed pursuant to the 2003 MS4 permit must be updated with significantly more detail added per the 2017 MS4 permit. You have 2 years to complete the update. If you are a new MS4 community subject to the 2017 MS4 permit, you need to start this process and complete it within 3 years. For all MS4s, the stormwater mapping must be updated annually; and catch basins, catchment areas, manholes, and other features must be added. You must also complete an outfall inventory and ranking. The ranking is based on potential for illicit discharges and sanitary sewer overflows. Are we having fun yet??

If flow is observed from any outfalls during dry weather, it will be necessary to conduct dry-weather sampling and testing of each outfall in which dry-weather flow was observed in order to determine if there are potentially illicit discharges in the outfall. Outfalls must be ranked as “Problem”, “High-Priority”, “Low-Priority”, or “Excluded” based on known or suspected illicit discharges or sewer system overflows. This is all part of the required Illicit Discharge Detection and Elimination Program (IDDE). Did I mention you need to complete a written IDDE program within one year (by June 30, 2019)?

A number of New Hampshire communities are specifically listed in the 2017 MS4 permit based on discharges to waters with an approved Total Maximum Daily Load (TMDL) and/or based on discharges to certain water quality limited (impaired) waters without an approved TMDL. Approved TMDLs include chlorides, bacteria or pathogens, and phosphorus.

How is your Phosphorus Reduction Plan coming along?
Impairments to waters without an approved TMDL include: nitrogen, phosphorus, bacteria or pathogens, chloride, total suspended solids, metals, and oil and grease. Did you know that leaf litter contributes phosphorus and nitrogen to stormwater runoff?

How is your Chloride Reduction Plan coming along?
The written Plan has to be completed within 1 year (on or before June 30, 2019). There are also specific requirements for public education and outreach as well as public participation including messages and outreach to target audiences.

How are your stormwater regulations?
MS4 communities need to update their stormwater regulations and ordinances (if you already have them) or develop and implement regulations for managing stormwater (if you do not have them).

By the way, did I mention that all of the foregoing has to be addressed in your Stormwater Management Plan? The Hoyle, Tanner team of experts is available to assist you as needed with MS4 permit compliance. If you have questions, please contact me or Heidi Marshall for assistance.

Hoyle, Tanner Engineers Showcase their Knowledge of Asset Management

Asset Management

On September 20, John Jackman, PE and Rychel Gibson, PE will be presenting on the basics of an asset management system at the Sunday River Grand Summit Resort Hotel & Conference Center in Newry, Maine, as part of the Maine Water Environment Association’s fall convention.

The focus of their presentation will be the documentation, organization and data collection for physical assets using tools like Google Forms. By using Google tools  (Drive, Calendar, Maps, and Forms), users can input data for free from a computer, tablet or phone. Among other tasks, John and Rychel will demonstrate how to use Google Forms to fill out daily logs and inspection sheets, and how to use Google Maps to document and track GPS assets.

Physical assets – like pipes, pumps, and valves — can be stressed from over-use, underfunding, and aging. It is the responsibility of the asset manager to know when an asset has reached its useful life. Over the past two decades, practical, advanced techniques have been developed for better managing physical assets. Hoyle, Tanner has assisted close to 40 municipalities, counties and state agencies with their asset management plans system. John Jackman has been involved with asset management for 16 years and joined the New England Water Environment Association in 2004. Rychel is a member of the Maine Water Environment Association and has been integrally involved with developing freeware-based asset management assistance during her time with Hoyle, Tanner.

 

john-and-rychel

The Flow of the River: What 2D Hydraulic Modeling Can Teach us about Movement

GIF image of 2D hydraulic modeling showing water under a bridge

Imagine trying to measure water in a beaker or in a measuring cup; it is stagnant and easy to follow the line of meniscus to see if it’s a ½ cup or 3/4. Then imagine measuring water in a river in order to build safer bridges; it tumbles over rocks, it changes speed, it experiences different water levels throughout a season.

Believe it or not, water movement is one of the most difficult phenomenon to solve. Yes, you can apply mathematics or numerical methods to solve complicated differential equations, but there are always some unknowns about turbulent flows (class 4 rapids) where general assumptions are made.

Rivers require intricate numerical models for river-type engineering problems, and I have been accepted to present on these intricate models at this years biennial National Hydraulic Engineering Conference (NHEC) in Columbus, Ohio. The Conference spans a week from 8/27 to 8/31, and I will be presenting on Friday, August 31st.

Per the NHEC website (https://www.ohio.edu/engineering/nhec/), the conference is themed “Advancing Hydraulic Engineering through Innovation and Resilient Design,” and will address the challenges that transportation agencies face to construct, maintain, sustain, and improve hydraulic structures in the physical, natural, social, and economic environments of today and tomorrow. At this conference, I will be presenting on Two-Dimensional (2D) Hydraulic Modeling with Tidal Boundary Conditions.

Modelers typically use computer software packages where you input topography, flows, roughness parameters, and hydraulic structures. The software package uses the input to solve mathematical equations. It seems simple enough, but a modeler needs to have a conceptual understanding of numerical methods and know the limitations of the software package being used.

Whenever you hear the term “3D,” you think of an object in a space that has 3-dimensions, right? Similarly, water moves within a 3-dimensional space, where there is a z-component (up, down), y-component (left, right), and x-component (back, forth). What if I were to tell you that the movement of water in the z-direction (up, down) is not considered?

What would that mean? Well, what that means is that mathematically, we are simplifying a very complicated problem:  we are restricting movement of water to flow/move in 2D, 2-directions (x and y) and that is what 2D hydraulics is all about. Similarly, a one-dimensional (1D) hydraulic model is defined when the y-direction is neglected and water is confined to moving in the x-direction.

2D hydraulic modeling is not that new and has been available in an academia setting since the 80s. But in recent years, tools to develop 2D models have been readily available to engineers. A 2D model can’t be developed for every problem that we tackle, but it allows us to accurately represent actual real world conditions, make less assumptions and judgment calls, and communicate and show visualizations of flow movement to stake holders.

Are you ready for the new NH MS4 Stormwater Permit?

Pond with lily pads

EPA Region 1 issued the revised New Hampshire Small MS4 General Permit on January 18, 2017. Affecting 60 New Hampshire communities, this new permit will make a significant change in stormwater management compliance when it takes effect on July 1, 2018.

This new permit imposes more stringent regulations for communities’ compliance in regards to how to manage stormwater.

Many community leaders have expressed concerns that the overlap with other regulatory requirements and the cost of meeting those requirements may not effectively achieve the desired results, and they are looking for integrated cost-effective approaches to meeting the new regulatory requirements.

Governor Chris Sununu has publicly spoken against the new MS4 permits, saying that they would severely impact municipalities and taxpayers, noting that “additional mandates contained within the new MS4 permit will prove themselves overly burdensome and enormously expensive for many of New Hampshire’s communities.”

If you live in community in Southern New Hampshire, chances are that this change affects you in some way. To see a list of affected communities, please visit the EPA website.

Hoyle, Tanner has experienced staff who are knowledgeable about asset management, SRF loan pre-application preparation, and MS4 permitting.

John Jackman, PE, asset management specialist

 

John Jackman, PE, is Hoyle, Tanner’s premier Asset Management Specialist. Although the CWSRF money cannot be directly used to support the MS4 program, using the asset management program to support documentation of municipal assets will be helpful in setting up a strategy for compliance related to the October 1, 2018 required filing date of the MS4 permit’s Notice of Intent.

 

Michael Trainque, PE, stormwater specialist

 

Michael Trainque, PE, has 39 years of environmental engineering experience.  Michael has been integrally involved in developing model stormwater regulations, identification, assessment and dry-weather sampling and testing of stormwater outfalls, as well as other aspects of stormwater management.

 

marshall

Heidi Marshall, PE has been assisting industries and municipalities with NPDES compliance since the 1990s when EPA published the initial stormwater requirements and can assist you with preparation of the Notice of Intent, developing or updating the Stormwater Management Plan, and can provide assistance with the required follow-up actions.

 

Hoyle, Tanner is equipped to help communities that are affected by MS4 regulation changes. We are immediately available to help with pre-application funding, notice of intent preparation for October, and setting up action plans to comply with MS4 requirements.

Let Hoyle, Tanner guide your community into a future with cleaner water. Contact John Jackman, PE for asset management application assistance, or for MS4 assistance, contact Michael Trainque, PE or Heidi Marshall, PE.

Engineers Week: Girl Day

Girl Day Engineers Week

It’s no secret that there is an underrepresentation of females in the field of engineering. Here at Hoyle, Tanner, we recognize diversity and inclusion as an instrumental part of making sure we are developing the best solutions to our region’s challenges. That is why we are participating in Girl Day, a recognized day of Engineers Week that is specifically geared toward generating awareness and educating young females about the opportunities available to them within the industry.

In 2015, women made up roughly 47 percent of the workforce but only 24 percent were working in STEM careers. Studies from Engineer Your Life & Changing the Conversation indicate that the lack of female interest and presence in the field may be due to the fact that many girls:

  • Do not know what engineering is
  • Think engineers must be exceptional at both math and science
  • Believe engineering is difficult and challenging

The gender gap in the industry can also be attributed to a matter of confidence. Studies show that when asked to assess their math abilities, female students tend to report lower capabilities despite equal levels of class achievement compared to their male counterparts.

There are many ways to encourage young girls to learn more about engineering, whether it be hosting events at your firm, visiting classrooms, or providing extensive access to role models or mentors within the field. However, if we are going to be successful in closing the gap and boosting the number of female engineers in future generations, we need to shift the focus of the conversation.

According to Discover Engineering, the only way to change young women’s thoughts about engineering is to change the way we talk about engineering. It is important to explain to young women that there is no “type” of person who becomes an engineer, and that a potential successful engineer does not necessarily have to be someone who “excels at math and science.” Instead, leaders of the women in the engineering movement suggest we begin to define a good engineer as someone who:

  • Is creative and imaginative
  • Likes to collaborate with others
  • Is curious and persistent
  • Wants to make a difference
  • Enjoys solving problems

By participating in Girl Day, we at Hoyle, Tanner hope to play our part in encouraging young women to study engineering. As a firm, we are proud to celebrate our female engineers and recognize how diverse minds at work help to increase the success of our projects.

Written by Grace Mulleavey

Happy National Engineers Week!

2018_engineers_week_logo_horizontal_0
Engineers Week Poster

(Image courtesy of DiscoverE.)

In the United States, National Engineers Week is always the week in February which encompasses George Washington’s actual birthday, February 22; President Washington is considered the nation’s first engineer. It is observed by more than 70 engineering, education, and cultural societies, and more than 50 corporations and government agencies. The purpose of National Engineers Week is to call attention to the contributions to society that engineers make. It is also a time for engineers to emphasize the importance of learning math, science, and technical skills.

This year’s theme, “Engineers: Inspiring Wonder,” is a call to recognize the people who create today’s awe-inspiring wonders like cloud-busting skyscrapers and human travel to Mars. Our lives would be very different without daily marvels like clean drinking water, computers, and cars.

Over the next week, we will:

  • Celebrate President’s Day and kick off Engineers Week;
  • Share the passion our employees have for engineering;
  • Visit a local high school to demonstrate the skills engineers use every day;
  • Celebrate Girl Day, a worldwide campaign to introduce girls to the fascinating world of engineering by vising a local Girls, Inc.; and
  • Attend the Engineer’s Week Banquet to celebrate the 2018 NH Engineer and Young Engineer of the Year.

For additional information on engineering or Engineers Week, we encourage you to visit http://www.discovere.org/our-programs/engineers-week

Designing Bicycle Box Systems to Keep Cyclists and Motorists Safe

Green box painted on pavement with bicycle riding on it in traffic

Everyone knows about bicycles. Like any sport, they have a fandom following, from avid Tour-de-Francers to all those dedicated bike-to-workers. Not to mention, it’s practically a rite of passage to learn how to ride one, and it’s the quintessential comparison when talking about things you never forget how to do once you learn.

Despite their popularity around the world, America still shines with its youthful glow in comparison to many historic countries; we just don’t have the same bicycle-laden streets that other countries have grown to cherish. That’s not to say that America isn’t making strides to enhance its bike-ability. Major cities have hundreds of miles of bike lanes, while New York City tops the list at having 1,000 miles.

Though America has some catching up to do, cities have seen overall betterment in roadway safety when communities define where bicyclists should travel on the roads.

One innovative design that’s gaining traction is the bicycle box. From the NACTO website, “A bike box is a designated area at the head of a traffic lane at a signalized intersection that provides bicyclists with a safe and visible way to get ahead of queuing traffic during the red signal phase.”

Bicycle boxes are innovative because they address many safety concerns at once, such as: increasing visibility of bicyclists, preventing “right-hook” conflicts, provides priority for bicyclists, and groups bicyclists into one obvious area, making it easier for cyclists to clear the area quickly.

Recognizing these benefits, Hoyle, Tanner recently designed a bicycle box system on Farrell Street in South Burlington, Vermont, which will become the first approved installation in the State. As Farrell Street is part of the route of the Champlain Bikeway (a 363-mile scenic loop around the lake), the City is dedicated to improving access and safety in this location and throughout the City. At the Farrell Street/Swift Street intersection, the City was particularly concerned that southbound cyclists looking to make a through or left turn would conflict with vehicles turning right to access US 7 & I-189. A bicycle box was the perfect solution. Hoyle, Tanner worked with the Federal Highway Administration (FHWA) and gained interim approval for the City’s use of this valuable tool, which is required for new traffic control devices that have not yet been formally adopted. Partnering with Howard Stein Hudson, Hoyle, Tanner designed the bicycle boxes which will employ special highly visible green pavement markings and thermal or video bicycle detection to reduce collisions and improve safety at the intersection. With this experience, Hoyle, Tanner will look to aid other municipalities and state agencies with this and other emerging traffic control technologies, with a goal of improving the recreational and commuter transportation experience for all users.

What Droughts can Teach us about the Importance of Proper Culverts

hillsboroughnh-stonearch

July 2016 struck New England with an extreme drought and dry weather patterns for an entire year in most of the region. Many people are seeing the drought disappear as heavy rainfall replenishes those dry wells. Showers are taken a little less guiltily.

Yet ironically, the seacoast areas of Maine and (some) of New Hampshire are still considered abnormally dry for this time of year. The drought.gov website says that the percent of dry conditions for the Northeast is a total of less than 10 percent. In general, around 90 percent have no dry conditions at all. Despite this time of year being dryer for the coast, long-term totals actually appear normal.

So, why the pesky persistence with this abnormally dry issue?

“Much of the Northeast remains drought free with the exception of coastal Maine, which has been plagued by below-normal precipitation over the summer,” Deborah Bathke reported in the National Drought Summary for August 8, 2017.

Lack of rainfall may seem relatively insignificant in the engineering world to some. Too much rainfall can cause road erosion, mud slides, sewage overflows, and building floods (among other glorious things). Too little rain? Aside from a crispy lawn, what could go wrong?

Well, for starters, a dry season can mean that ground water levels are low. Low water levels mean that engineered structures, like culverts, don’t work like they are supposed to. Which can lead to problems for an entire ecosystem.

Culverts are a great example. Culverts allow for water passage — such as streams, creeks and brooks — to move under roads. Many aquatic species migrate during their lifetimes, so in order to do that, they need to be able to swim or wade through water freely. The National Oceanic and Atmospheric Administration (NOAA) explains that incorrectly engineered or installed dams and culverts can contribute to declining fish populations by not allowing continuous water flow and creating a physical barrier to fish passage. Throughout the watershed, there can be several examples of perched road crossing culverts (where a drop in elevation exists between the end of the culvert and the water body) and culverts that are too narrow, steep or collapsed.

As rain levels increase and droughts are ending, aquatic life has the chance to move more freely through these constricted passageways.

The importance of culverts can be partly attributed to the way the water flows.

culverts

 

The New England states have turned their attention to the importance of designing culverts that are eco-friendly for the past two decades, with regulations in place in each of the five states that require certain levels of flows, both high and low, to be maintained through culverts in order to protect migrating organisms. From an article by the US Fish & Wildlife Service of Alaska comes the challenge to make roads more fish-friendly:

“What’s under our roads should ideally mimic what’s upstream and downstream,” the article says. “This helps ensure a seamless transition for fish passing underneath. … So how wide is wide enough? To answer that, we must understand the stream’s range of flows. A stream gauge that tracks water level and documents flood events over time can help.”

When accurate stream gauge data is not available, particularly for the smaller creeks or brooks, engineers must examine the existing conditions and develop assumptions on flows, typically using hydrologic models that are standard industry practice.

In short, as you drive from place to place during your day, take time to notice the road culverts you pass over. They have an important role in keeping an ecosystem functioning at its best, even under drought conditions.

14 Steps for Preserving Steel Structures

Piermont, NH-Bradford, VT Steel Bridge

Preventative maintenance is defined as scheduled work at regular intervals with the goal to preserve the present condition and prevent future deficiencies. On bridge structures, this work is typically performed on structures rated in ‘fair’ or better condition with significant service life remaining. Minor repairs may be necessary to maintain the integrity of the structure and prevent major rehabilitation. Structures that are not maintained are more likely to deteriorate at a faster rate and require costlier treatments sooner than maintained structures; therefore, it is more cost effective to maintain structures to avoid replacement or major rehabilitation needs.

New England’s weather causes extreme conditions for steel bridge trusses, such as flooding, ice and snow. Corrosive de-icing agents are used in the winter, which can accelerate deterioration of exposed bridge elements. Preventative maintenance is critical for steel truss bridges to reach their intended design service life and, therefore, attain the lowest life-cycle cost of the bridge investment. Presented are minimum recommended guidelines for preventative maintenance of steel truss bridges.

Here are 14 actionable maintenance tasks to preserve historic truss bridges:

  1. General: Remove brush and vegetation around structure. Annually.
  2. Bridge Deck & Sidewalks: Sweep clean sand and other debris. Power wash with water to remove salt residue. Annually.
  3. Wearing Surface: Check for excessive cracking and deterioration. Annually. 
  4. Expansion Joint: Power wash with water to remove debris, sand and salt residue. Annually.
  5. Bolted Connections: Inspect for excessive corrosion or cracking of the steel fasteners. Check for any loose or missing bolts. Annually.
  6. Welded Connections: Check for cracking in the welds. Annually.
  7. Truss Members: Power wash with water to remove sand, salt and debris, particularly along the bottom chord. Give specific attention to debris accumulation within partially enclosed locations such as truss panel point connections or tubular members. Annually.
  8. Bridge Seats: Clean around bearings by flushing with water or air blast cleaning. Annually.
  9. NBIS Inspection: Complete inspection of all components of the steel truss bridge. Every 2 years unless on Red List.
  10. Painted Steel: Scrape or wire brush clean, prime and paint isolated areas of rusted steel. Every 2 to 4 years.
  11. Steel Members: Check for rust, other deterioration or distortion around rivets and bolts, and elements that come in contact with the bridge deck which may be susceptible to corrosion from roadway moisture and de-icing agents. Every 3 to 5 years.
  12. Bearings: Remove debris that may cause the bearings to lock and become incapable of movement. Check anchor bolts for damage and determine if they are secure. Every 3 to 5 years.
  13. Exposed Concrete Surfaces: Apply silane/siloxane sealers after cleaning and drying concrete surfaces. Every 4 years.
  14. Bridge & Approach Rail: Inspect for damage, loose or missing bolts, sharp edges or protrusions. Every 5 years.

Actions to Avoid

  • Do not bolt or weld to the structural steel members.
  • Do not remove any portion of the structure.
  • CAUTION! Paint may contain lead.

Additional resources can be found through the New Hampshire Division of Historical Resources website.

How Your Community Plays a Part in National Walk to Work Day

IMG_1665-Web

Spring has arrived just in time for National Walk to Work Day! Individuals across the country are lacing up their sneakers and hitting the pavement, while communities are taking a more holistic approach to ensuring safe pedestrian and bicycle travel. Many municipalities are introducing the concept of “complete streets”, introduced by the National Complete Streets Coalition, to their design efforts to balance safety and convenience for motorists, transit users, pedestrians and cyclists alike. Currently, there isn’t a single design for a complete street; it represents creating roads that are safe for all users, regardless of age, ability, or transportation method. Growing in popularity, some of the complete streets features are being implemented throughout the state, including:

Traffic Calming
With the growing demand for alternative modes of transportation, traffic calming measures are being introduced on various roadways to ensure safe travel for all users. The use of narrowed throughways, speed bumps/humps/tables,chicanes, and curb extensions (bulbouts) are some of the many features being used in the efforts to slow automobile travel, including the Union Street Reconstruction in Peterborough, New Hampshire. This project also incorporated tree plantings along the medians to beautify the area.

High Visibility Crosswalks
History shows pedestrian crossings existing more than 2000 years ago, where raised blocks on roadways provided a means for pedestrians to cross without having to step on the street itself. In current designs, high visibility crosswalks are incorporated to guide pedestrians and alert motorists to the crossing locations. Six foot wide crosswalks are installed using long lasting plastic/epoxy or paint embedded with reflective glass beads to assist in the crossing markings. In addition to local governments, universities, like the University of New Hampshire, are incorporating these crosswalks on their campuses.

Shared Use Paths
A multi-use path or trail that has been separated from motor vehicle travel and has been established for alternative transportation purposes is another option that is growing in popularity. Utilizing existing right-of-ways to create these travel corridors for pedestrians, cyclists, skaters, equestrians, and other non-motorized users in some instances are also used to observe the natural environment in various communities. Recently, a shared use path was completed connecting Manchester’s and Goffstown’s trail system.

Multi-Modal Intersection
Intersections have the unique responsibility of accommodating and coordinating the nearly-constant occurrence of conflicts between all modes of transportation. Multi-modal intersections focus on intersections where numerous modes of travel come together and the coordination is required for the safety of all users. Utilizing different design features such as corner refuge islands, forward stop bars, and dedicated bike lanes, as used on Manchester Street in Concord, all intersection users can travel simultaneously, safely.

With many communities implementing these design features into roadway geometry, walking to work can be as simple as strapping on your shoes and heading out the door. By walking to work for this nationally recognized day, you will help reduce carbon emissions, get fit, and avoid the traffic jams.

Pi vs. Chocolate Cream

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Pi… I did not forget the “e”, I am referring to the mathematical constant, π, for the value 3.141592…, a ratio of the circumference of a circle to its diameter. For some it was junior high and others it was high school, but almost everyone is taught the concept of Pi in geometry class in America. The staggering question asked by so many students over the years is “how do we use this in ‘real’ life?” Well we have answered that question for all of you as it relates to engineering:

When designing bridges many of the structures utilize reinforced concrete to provide the strength necessary to support its daily use by vehicles. For many of our bridge projects, the circle is most often representing the area of reinforcing steel used in the reinforced concrete beam.  We determine the total amount of the (steel) reinforcing to determine the capacity of a structural member such as a beam, deck or slab.

In associated roadway design, Pi is used in a slightly different manner, to calculate curvature. A maximum curvature (minimum radius) is used to ensure adequate sight distance at differing speed limits. This promotes safe vehicular travel by providing a level of comfort and expectation to the driver.

Another application for the mathematical constant is in airfield markings. Their purpose is simple – to safely guide pilots during aircraft take-offs and landings, and while taxiing around the airfield. To create these markings, Pi is utilized when calculating the amount of airfield paint required for runway designation markers, taxiway centerlines and edge lines.

Pi is also used extensively in the calculation of areas of gravity sewers, wastewater force mains, water main pipes, storm drains, drainage culverts and other types of utility pipes. These calculations are used to establish the area of the pipe for the purpose of determining flow velocities and flow volumes as well as other types of hydraulics calculations.

Now that we have proved your mathematics teacher correct, and that someday you may need to know the value of Pi, the obvious question remaining is “what does pi and pie have in common?” My answer is Pi is focused on circles, radius and diameters… and so does pie! If you want a great Chocolate Cream Pie recipe check this out!

“Climbing” the Memorial Bridge

Bridge inspection is an important part of what we do here at Hoyle, Tanner. It is also a vital part of ensuring the safety of the traveling public across the country. You might not realize it, but chances are every time you get in a car you drive across one or more bridges. Per the federally enacted National Bridge Inspection Standards (NBIS) every bridge, big and small, old and new, needs to be inspected on a biennial basis. As you can imagine, this is a huge undertaking for each state’s department of transportation (DOT), and each DOT is looking to inspect bridges faster, more cost effectively, and in less disruptive ways as to not impact the day to day usage of the bridge.

A dynamic, rapidly growing bridge inspection method is to “climb” the structure using rope access techniques. Rope access can best be pictured as a mixture of rock climbing and bridge inspection. The inspector is suspended from two ropes and can either ascend, descend or climb along the bridge. Certain bridges can often have elements that are inaccessible or uneconomical to inspect with traditional methods, such as rigging or the use of under bridge inspection vehicles. Rope access can be tailored for countless geometric challenges, which allows for a detailed, hands-on inspection of every bridge element. In other words, rope access allows inspectors to go anywhere and see any part of the bridge.

Recently a team of five Hoyle, Tanner bridge inspectors including three SPRAT1 and/or IRATA2 rope access inspectors completed a bi-annual inspection of the Memorial Bridge in Augusta, Maine. This 2,100 foot long, 75 foot high historic deck truss bridge posed many challenges for bridge inspection access. Access from the ground below was limited because part of the bridge is over the Kennebec River, and access from above was prevented by a tall chain link fencing that runs the entire length of the bridge. Most importantly, this bridge is a vital transportation route in the heart of the state capital making closing all or part of the bridge to traffic undesirable. Utilizing rope access techniques, we were able to perform a hands-on inspection of every member of the bridge from below the deck and above the river. Rope access allowed for a faster and more cost effective inspection than the traditional methods typically used.

  1. Society of Professional Rope Access Technicians– North American body for developing rope access standards and practices.
  2. Industrial Rope Access Trade Association– Internationally recognized body for developing rope access standards and practices.

First Response: Storm Damage Mitigation of BMP Failure Presentation

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I didn’t know what to expect. I had been to conferences before, seen many presentations, but never had to give one of my own. I thought, why not, I can do this. I got off the plane in Austin on Monday night and took the bus to the hotel. I had just missed the welcome social hour so I decided to relax before two full days of conference proceedings.

I got up early Tuesday morning to practice my presentation, although I wasn’t supposed to present until the following day. I got ready for the day and attended various half hour presentations about best Management Practices (BMP) Case Studies, Green Infrastructure, and Advanced Research Topics. Over a hundred vendors were gathered in one room promoting their products and answering questions. Tuesday night ended with a gala for all the conference exhibitors, speakers, and attendees. I met various engineers, managers, and product specialists.

Wednesday morning started early, like Tuesday, with me practicing my presentation before my 10:00 AM time slot. I got to my conference room early so I could set up and just as I fumbled through some minor technical difficulties, attendees started filling the room. Ten… twenty… fifty – I could not keep up with the headcount – All I knew was it was a full house. The moderator introduced me by reading my biography and as I stood up, I took a deep breath and started presenting. I knew what I wanted to say. I knew what slide was next. It was just like I had practiced. I had 30 minutes to present; but finished in 20 – a little fast, but I nailed the important discussion points.

I wanted to emphasize the intensity of the storm that caused the erosion at the airport. I wanted to emphasize the magnitude of the erosion along with the length and steepness of the eroded slope. And finally, I wanted to emphasize the various stormwater BMPs that were used in the design of the slope stabilization to prevent future failures along with the short amount of time available to do the design. I explained the various detention ponds and the closed drainage system that we designed to convey the stormwater from the top of the hill to the bottom. I showed details of the detention ponds and swales along with the different types of stabilization we used on the steep slopes.

It was now time for questions. What were they going to ask and would I be able to answer them? Three questions were asked and confidently I was able to answer them. I knew why we did what we did and what the design controls were and could therefore speak confidently about why we came up with the design we did.

And then it set in… it was over and I nailed it. Breathing resumed. It felt good to be done and to feel good about my presentation.

7 Factors in Snow Load Evaluations

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The weight of one foot of fresh snow ranges from 3 pounds per square foot (psf) for light, dry snow to 21 psf for wet, heavy snow. When evaluating an existing roof for snow loads, an engineer will want to know the year it was built, the materials involved and the load the roof was designed to support, to start. But there are many other variables that need to be considered when evaluating existing roof loads under snow conditions. Outlined here are some of the many factors that impact the snow load carrying capacity a structure:

  1. Materials & Design:Engineers use the building code formulas to determine the appropriate snow load for their new design.  A detailed study, prepared in 2002, set the ground snow loads throughout New Hampshire and is the basis for all new construction projects.  Structural engineers use various design standards for steel, wood and concrete that include factors of safety and account for serviceability issues such as deflection. Older structures, governed by earlier building codes, may not meet current standards.
  2. Detailing and Construction:The type and condition of the bracing and roofing materials can contribute to (or undermine) its strength. Some older steel framed buildings used a cantilever beam layout to minimize the beam sizes by using the load of one beam to reduce the stress in the adjacent beam. Because snow buildup occurs in an unbalanced manner, roof failures have been attributed to this type of construction. Minor renovations to an existing structure can reduce the carrying capacity when, for example, bracing is removed to add new ducts.  A recent study, published in STRUCTURE magazine, found that the bulk of New England roof failures were related to construction or detailing deficiencies and were not a result of excess snow loads.
  3. Pitch & Thermal Conditions:The slope and type of roof surface determines how much snow is retained on the roof. Flat and low-pitch roofs are more commonly prone to overloading because they hold onto snow more easily than steeper ones. Flat roofs without adequate drainage are at increased risk of failure due to ponding that occurs as a result of excessive deflection. Adding insulation to the structure reduces the heat loss causing less melting, and results in larger loads. Similarly, the absence of any heat will increase the snow retained even more.
  4. Roof Layout Geometry:The location of hips, valleys, high roofs and low roofs, and raised elements – like skylights and dormers – create snowdrifts and therefore factor into determining additional loading. Similarly, the addition of snow guards on a sloped roof change the dynamics of the snow behavior on the roof. Parapets and large roof top equipment can cause snow drifts on flat roofs. The addition of a new structure adjacent to existing structures often create drift conditions that are not accounted for adequately during renovation projects.
  5. Depth and Snow Density:Determining the weight of snow based on depth is not possible unless you know the density of the snow on a particular roof. The density is the weight of the water in a set volume of snow. Snow on a roof will compact over time as temperatures fluctuate and as new snow layers are added to the roof. Rain-on-snow increases the density of the snow thus increasing the weight. Measuring this density is not terribly scientific and is not as important as how the roof is actually performing.
  6. Sun and Wind Exposure:Natural elements such as sun and wind impact how much snowfall is retained on a roof. From a code perspective, 70% of a single snowfall event is expected to remain on a roof under normal wind conditions. Wind and sun can create unbalanced snow load conditions on a gable roof when more snow is retained on one side of the ridge than the other.
  7. Maintenance:Proper, or improper, maintenance plays a role in how well a building will perform under load. Some older roofs suffer from steel beam and connector corrosion, or rotting wood, which reduces the building’s ability to withstand heavy snow loads. Proper maintenance, including repairs to any damage or leaks, is important to ensure the structural integrity of the entire structure.

For more information, please contact our Building Structural Department .

5 Facts About Sustainable Stormwater Practices

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In urban areas where numerous impervious surfaces are found, stormwater runoff is a significant contributor to water pollution. As rain falls in suburban and rural areas, the rain water is absorbed and filtered by the natural vegetation and soil in those areas. The impervious surfaces, including roofs and pavement, do not allow the ground to absorb the water therefore it is discharged without filtration into local water bodies either as direct runoff or through drainage systems.

Here we review 5 Facts About Sustainable Stormwater Practices to help communities and agencies thinking about developing new Green Infrastructure.

  1. Regulatory Compliance:Stormwater is regulated by the Environmental Protection Agency (EPA) under the Clean Water Act (CWA). This “establishes the basic structure for regulating discharges of pollutants into the waters of the United States and regulating quality standards for surface waters.” Thus making it “unlawful to discharge any pollutant from a point source into navigable waters, unless a permit was obtained.”1 In addition, some communities have developed Stormwater Management Plans to assist in the management of discharge from both private and public properties. Ordinances are used by local governments as an integral part of the municipal review of subdivisions and site plans diverting the cost with the use of fees charged for review of subdivisions and site plans. New stormwater regulations are being integrated into subdivision and site plan regulations to require implementation of sustainable stormwater management practices.
  2. Green Materials:“Green” or sustainable stormwater best management practices treat stormwater as a resource to be preserved and maintained, taking advantage of natural processes to clean and filter stormwater runoff. Vegetation and soil filtration highlight the obvious green materials used, but some methods growing in popularity include permeable pavement, down spout disconnection, rainwater harvesting, rain gardens, planter boxes, tree filters, green roofs, bioswales, as well as land conservation. With the incorporation of one or more of these design features, urban spaces will create less impervious surfaces thus reducing the amount of stormwater runoff.
  3. Public-Private Partnerships:State and local governments collaborating with developers on properties within different regions to incorporate Green Infrastructure into the design/redesign will in turn save money via diversion and treatment by the agencies. By offering tax credits or incentives to the developers, the adoption of these practices may grow quickly in popularity and use.
  4. Funding Availability:Many funding options are available through federal and state agencies including EPA, DOT, EDA, HUD, NOAA, as well as the Departments of Agriculture, Energy and Treasury. The available grants through these agencies will allow for municipal and private entities to make sustainable upgrades to existing or redeveloping sites.
  5. Benefits:Environmental – Increased stormwater, entering our water systems, contains pollutants from the surfaces it is diverted from potentially causing contaminated habitats for aquatic vegetation and wildlife. It can also cause physical problems such as erosion and flooding. With the use of Green Infrastructure, contaminants can be reduced in the receiving water bodies and create healthier environments. Social – Incorporating sustainable stormwater management practices can improve water quality, quantity and aesthetics thereby enhancing the livability of a community, create multifunctional landscapes and green spaces, encourage revitalization, and provide educational opportunities. Economic – The use of Green Infrastructure may provide opportunities to attract investment; reinvigorate deteriorating neighborhoods; inspire redevelopment; or provide recreational openings.

To find out more about community stormwater management practices, the EPA has issued a new guidebook outlining practices to assist while achieving other environmental, social and economic benefits. http://www.epa.gov/smartgrowth/green-infrastructure.html

1 http://www2.epa.gov/laws-regulations/summary-clean-water-act