The T&H Blog Archives - Page 19 of 30

Water Crisis in the United States, Part 2: Crumbling Infrastructure

Continuing our July theme on water crises in the United States, this week’s article will dive into our nation’s deteriorating water infrastructure — and how we can fix it. America’s infrastructure is in serious trouble, especially our water systems. Although the quality of drinking water in the U.S. remains high, our aging water infrastructure can no longer be ignored. Many of the pipes are over 100 years old and are exceeding their useful life. We experience about 240,000 water main breaks each year, or one every two minutes. These breaks result in 1.7 trillion gallons of clean water wasted annually. If not replaced, these water systems are expected to cost over a trillion dollars in repairs in the coming decades and, more importantly, put people’s health at risk.

The State of Our Infrastructure

Every four years, the American Society of Civil Engineers (ASCE) develops a report card that depicts the condition and performance of American infrastructure. Our water and wastewater infrastructure both received a D grade, which is a slight improvement from the 2009 report card which ranked both water and wastewater at a D-. Despite the subtle improvement, our country has a long way to go to bring our water systems up to date and make them adequate for future demands.

We as citizens have become blind to our failing infrastructure by accepting preventable environmental hazards as the norm. Events such as polluted and toxic drinking water, floods from levee failures, lead contamination, and constant pipeline bursts have become all too common in our nation. It is apparent that there is a pressing need for modernization, reliability, and long-term funding. Despite these alarming scores and figures, we can improve the current condition of our nation’s infrastructure if we take the right steps.

What We Can Do Now

A section of pipe showing extreme clogging

One of the best ways municipalities and water companies can improve and monitor their aging water systems is pipe testing. Testing the strength of pipes provides insight on how likely a system is to fail or leak. Pipe testing also helps to identify areas of a water system needing repairs, which can save millions of gallons of water as well as a lot of money.

Another way to assess a water system is with an annual water audit. Water audits help municipalities and water companies figure out how to address non-revenue water (NRW). NRW is water that is pumped into the system but not accounted for due to leaks, theft, customer metering inaccuracies, and other inaccurate accounting of water use. Effective water audits can reduce the need for facility upgrades and expansions, reduce the need to find additional sources, and help protect public health by reducing the number of entry points for disease‐causing pathogens.

Although pipe testing and water audits assist in monitoring and improving water systems, the real solution is long term replacement through government and legislative action. To do so, we need to accomplish three important goals:

Increase leadership in infrastructure renewal. We need bold and compelling vision at the national level if we plan on getting anything done. A way we can make this happen is to tell our legislators to take action.

Promote sustainability and ongoing maintenance. Our infrastructure must meet our present and future demands as challenges continue to arise. Our water system problems are not just a one time fix; we need plans in place to monitor and maintain our systems for growing future demand.

Develop, prioritize, and fund plans to maintain and enhance our infrastructure. Once funded, infrastructure projects must be prioritized in ways that improve people’s lives and support a thriving economy. Fixing our infrastructure is going to be expensive. We need to prioritize future improvements based on the benefits and demand of the improvements so we can best serve everyone across the country. Everyone deserves clean, safe drinking water.

What to Take Away

The truth is, there is too much at stake to keep ignoring our weakening infrastructure. If we do not do something soon, Americans may be in for some serious surprises. Imagine not being able to drink the water that comes out of our faucets or even take a shower without worrying about water borne diseases and bacteria. If we wish to seriously improve our water infrastructure, we need collaboration from all parties, both public and private. Politicians and lawmakers need to take definitive action and commit to a sustainable and reliable plan to make our water systems safe and adequate for the future. We need to make the condition of our country’s water systems a top priority.

Water Crisis in the United States, Part 1: Navajo Nation

Water poverty has long been considered a global crisis, with over 783 million people worldwide — that’s one in nine people — lacking access to a safe, clean water supply. Over half of the world’s hospital beds are filled with people afflicted with water-related illness, and over 80% of illnesses in sub-Saharan Africa are directly attributable to poor water and sanitation conditions. There are a plethora of charities dedicated to solving the global water crisis, including Tata & Howard’s and AWWA’s charity of choice Water For People. However, there are also water crises taking place right here in the United States. For the month of July, we will be delving into water crises in the United States — and how we can work together to solve them.

Navajo Nation

Last fall, CBS Sunday Morning News ran a cover story titled The Water Lady: A Savior Among the Navajo. The piece showcased Darlene Arviso, a Saint Bonaventure Indian Mission employee who delivers water to the people of Navajo Nation. Prior to that, the American people were largely unaware of the water crisis afflicting a full 40% of the 173,000 residents of Navajo Nation.

Navajo Nation, though located within the borders of the United States, is a soverign nation with its own president, and does not fall under the jurisdiction of the United States government. Therefore, it also does not fall under the jurisdiction of the Safe Drinking Water Act, which regulates all 155,000 public water supplies of the United States and ensures that our drinking water is safe and clean. Water poverty affects all aspects of life, including not only health and longevity, but also livelihood and education. Unfortunately, the people of Navajo Nation are no exception.

Many of the residents of Navajo Nation must travel many miles to gather water, the most fortunate of whom typically travel by car. However, a large percentage of these residents live well below the poverty level and can ill afford the cost of gasoline required to travel to gather water. Others must walk several miles — no different from their sub-Saharan counterparts. To make matters worse, the water they gather is often from livestock troughs or unregulated wells, frequently fouled by bacteria and other contaminants.

EPA warning to residents of Navajo Nation

Adding insult to injury, much of the water in Navajo Nation is contaminated with uranium and arsenic due to the prevalence of mining that took place in the area during the nuclear arms race. Uranium and radioactive particles have been found in much of the water supply in Navajo Nation, and the rest has been contaminated by coal mining and coal-fired power plants. At this point, basically all of the water of Navajo Nation is contaminated in some way, which has affected the health of the citizens there. Nearly half of the residents have been touched by kidney ailments or cancer. Since the Navajo people now understand that the water in their land is poisonous, they are forced to travel even farther to find safe water. Some of the residents save up their money for gasoline and make the four-hour trek to Flagstaff, Arizona to buy bottled water when it is on sale.

Solving the Navajo Nation Water Crisis

"Baby Lisa" — photo courtesy of Navajo Water Project — “Baby Lisa” — photo courtesy of Navajo Water Project

Fortunately, the Navajo water crisis is finally receiving the attention it deserves. Navajo Water Project, a subsidiary of DIGDEEP, is the sole water charity dedicated to the Navajo water crisis in the United States, and has a mission in which Tata & Howard firmly believes. Working with the Saint Bonaventure Indian Mission and subsisting on private donations, Navajo Water Project digs wells, installs water storage tanks, and brings in-home plumbing to those suffering from water poverty in Navajo Nation. Most recently, the Navajo Water Project issued a plea for Baby Lisa, a Navajo child born with Microvillus Inclusion Disease. Her illness requires her to have a feeding tube, for which she needs clean water. Without clean water, she could become seriously ill or even die, so Baby Lisa was living in a medical facility over three hours from her family home. The Navajo Water Project petitioned individuals and businesses for $50,000 to bring clean water to Baby Lisa’s home, and this past spring, they surpassed their goal. The Project is now in the process of installing plumbing in the family home.

Secretary of the Interior Sally Jewell signed an agreement in 2015 guaranteeing the water rights of the Shoshone-Paiute Tribes in Nevada and ensuring water supplies and facilities for their Duck Valley Reservation. Joining Secretary Jewell in a signing ceremony was Shoshone-Paiute Chairman Lindsey Manning. — photo courtesy of nativenewsonline.net

In addition to the Navajo Water Project, the Navajo have entered into agreements with the United States government. Since 1978, native Americans have entered into deals with the U.S. Department of the Interior in which they procure funding for their nation’s water supply in exchange for relinquishing some of their water claims to the federal government, states, and private investors. Additional deals are currently underway, including one in Utah that passed in January of this year. The deal secured millions in funding to build water infrastructure such as distribution systems and treatment facilities on Navajo land. And while many Navajo see these deals as the only way to improve their quality of life and support economic growth, others worry that by relinquishing their water rights they are essentially stealing from future Navajo generations who, if climate change progresses as predicted, may find their water supply has run dry.

In Conclusion

The answer to solving the water crisis of Navajo Nation is not simple. Bringing safe, clean water to the people of Navajo Nation will require both public and private investment. It will also require fair legislation that allows the Navajo to keep rights to water on their land while requiring the federal government to fund the cleanup of the waters that they contaminated. The nation has been in an uproar over the water crisis in Flint, Michigan, in which hundreds of children suffered from lead poisoning from their water supply. However, we should also be outraged at the decades of water poverty and contamination that the people of Navajo Nation have endured. The time has come to address the water crisis in Navajo Nation and to ensure that ALL people living on U.S. soil are afforded the most basic human right to water.

Meeting Wastewater Utilities’ Needs Through Capital Efficiency

Wastewater. It’s something that will always exist, and will always require collection and treatment. Just like improved water, improved sanitation is one of the key contributing factors to a developed nation, significantly improving public health, educational opportunity, and workforce viability. And while the United States boasts nearly 100% improved water and sanitation, there is still cause for concern.

In the American Society of Civil Engineers (ASCE) 2013 Report Card, wastewater received a “D” grade. Why? Because our existing infrastructure is in desperate need of repair and replacement, and a significant funding gap exists. This gap can be attributed to the fact that funding has been declining while regulations continue to increase.

In March of 2015, the Congressional Budget Office (CBO) published a report on annual government expenditures on infrastructure, titled Public Spending on Transportation and Water Infrastructure, 1956 to 2014. The data, collected from the Office of Management and Budget (OMB) for federal expenditures and from the Census Bureau for state and local government expenditures, indicates that federal, state, and local governments in the United States have been investing LESS in water and wastewater infrastructure than ever before. From 1956 to the late 1980s, total government spending increased in real dollars by approximately 3%-4% per year, and then from 1%-2% through 2009. These expenditures include both capital and operations and maintenance (O&M) costs. However, from 2010 until present, total government spending has actually decreased by 8%.

To further complicate matters, capital expenditure has decreased at a faster rate than O&M expenditure. From 1956 to 1980, public spending was basically split between capital expenditures — to build or replace water and wastewater systems — and O&M of the systems. However, since 1980, O&M spending continued to grow at an annual rate of 4%-6% to the 1990s, and then at an annual rate of 1%-3% through 2009, since when it has remained flat. In contrast, capital spending grew at an annual rate of only about 1%-2% since 1980, and has declined at an average annual rate of 4% since 2009. Governments now spend twice as much on O&M of their existing systems than on capital expenditures to repair, rehabilitate, or replace existing assets or for the installation of new infrastructure. In addition, state and local government is now saddled with nearly the full burden of capital expenditure, as federal spending has been steadily on the decline since 1976.

Clearly, municipalities are faced with the almost insurmountable task of staying up to date with all current regulations while also improving outdated and failing systems. Because wastewater collection and treatment is such a crucial aspect of modern day society, it has become paramount that municipalities find cost-effective and efficient ways of maintaining and updating critical infrastructure.

One of the most effective ways in which municipalities can intelligently allocate their limited infrastructure dollars is by implementing a clear and systematic plan of action for capital improvement projects. Typically, asset management is considered to be the standard by which wastewater utilities address capital assets. Defined by the EPA as managing infrastructure capital assets to minimize the total cost of owning and operating them, while delivering the service levels customers desire, asset management certainly plays a key role in smart capital planning. However, asset management should only be part of the equation. Hydraulic modeling and system criticality are two equally important aspects which should be examined when planning long-term capital expenditure.

Tata & Howard’s Wastewater Capital Efficiency Plans™ identify those areas of your wastewater systems needing rehabilitation, repair, or replacement that make the most efficient use of your limited infrastructure dollars by combining the concepts of hydraulic modeling, system criticality, and asset management into a single comprehensive report. Each report is tailored to the individual utility distribution system and provides utilities with a database and Geographic Information System (GIS) representation for each pipe segment within their underground piping system. The CEP report then prioritizes system piping improvements and provides estimated costs for replacement and rehabilitation.

Our three circle approach includes the following:

Hydraulic modeling

Model verification if available
Compare flows with design carrying capacity
Hydraulic deficiencies
History of SSOs
High infiltration/inflow rates

Critical Components

Interceptors
Trunk sewers and force mains
Residential sewer mains

Asset Management

Establish score for each pipe segment based on blockages/collapses, I/I rates, installation year, soil corrosivity, PACP structural and maintenance ratings, and other criteria.

A comprehensive CEP provides a utility with not only a prioritized list of logically thought out infrastructure projects, but also a justifiable and defendable plan of action to present to town administrators when planning budgets.

To continue as a leading industrialized nation, our wastewater utilities must not only remain safe and functional, but also progressive and up to date with current and future regulations. Because funding is declining while costs and population are increasing, it is more important than ever for wastewater utilities to methodically prioritize and plan all repairs and improvements. Only through the implementation of a well-researched and systematic course of action will utilities be prepared to provide safe and dependable wastewater services both now and in the future.

A Roadmap to Massachusetts MS4 Stormwater Compliance

The long-anticipated 2016 Massachusetts Small MS4 General Permit, which replaces the 2003 Small MS4 General Permit, was finally signed on April 4, 2016 and jointly issued by the U.S. EPA and MassDEP on April 13, 2016, with an effective date of July 1, 2018. While this date may seem a long way off, it actually affords municipalities limited time to efficiently and effectively determine Massachusetts MS4 compliance needs.

The Time to Plan is Now

Marlborough-stormwater-pretty-300x225 In addition to the six Minimum Control Measures included in the original 2003 Permit, the 2016 Massachusetts MS4 General Permit also specifically includes limits to Total Maximum Daily Loads (TMDLs). TMDLs set pollution limits for affected waterways. These pollution limits represent the maximum amount of pollutant a specific body of water can handle before marine life, wildlife, and/or recreational uses become adversely affected. Because stormwater has the potential to have a significantly negative impact on waterways, TMDLs are a necessary protection measure. Unfortunately, addressing stormwater contributions to TMDLs will require that many communities make some structural and treatment modifications to their stormwater systems, and these take both time and money.

A Notice of Intent (NOI) to apply for coverage under the Permit must be filed to the Massachusetts Department of Environmental Protection (MassDEP) by September 29, 2018. The Permit is expected to increase municipalities’ stormwater costs substantially for the duration of the permit term — an increase that simply may not seem affordable to some communities. And, non-compliance is not an option as it brings with it its own costs including the potential for regulatory action and fines.

The best course of action to establish compliance with the 2016 Massachusetts Small MS4 General Permit is a proactive, systematic approach. Municipalities should be evaluating current MS4 stormwater measures including stormwater system mapping, best management practices (BMPs), illicit discharge monitoring and elimination, etc., and assessing whether or not they are still in compliance with the new Permit. In addition, municipal stormwater systems should be carefully evaluated for cost-efficient and effective means of becoming fully compliant as well as provided with a proposed 5-year budget for compliance. In this way, small MS4 stormwater systems can approach local government officials with a clear and defendable stormwater budget so that nobody is caught unprepared..

Mid-CityScrap_condition1-225x300 Fortunately, stormwater assessments that are conducted by licensed professional engineers, such as Tata & Howard’s MS4 Compliance Assessments, provide a significant return on investment. As part of the assessment, the entire system is meticulously evaluated for the most budget-conscious ways in which to fully meet compliance. Permit exclusions will also be assessed and all previous stormwater work will be documented to establish proper credit. The assessment also provides a well-planned course of action that is defendable when justifying projects and procuring funding.

Key Dates:

July 1, 2018: Revised MS4 Permit effective date
September 29, 2018: Notice of Intent (NOI) to apply for coverage under the permit due to EPA/MassDEP (90 days from effective permit date)
July 1, 2019: 5-year Stormwater Management Plan (SMP) must be posted publically (one year from the effective permit date)

While the 2016 Massachusetts Small MS4 General Permit has received critical attention and is likely to increase municipalities’ stormwater costs, it is also likely to significantly increase protection to the Commonwealth’s waterways. The fact also remains that the revised MS4 Permit has already been signed and issued. Therefore, finding a balance between compliance and budgetary constraints must be a priority for all MS4 communities.

JonGregory400-150x150

Jon Gregory, P.E., Tata & Howard’s Stormwater Manager, has dedicated his career to water environment engineering consulting and has over 18 years of experience in the design, permitting, and construction of water related projects. He is currently working on numerous stormwater projects throughout Massachusetts including assisting communities with MS4 compliance.

Water Mains — Then and Now

Water mains play a crucial role in modern day civilization and contribute greatly to public health. Water mains have been in use for over 4000 years, and, through the years, huge strides have been made in the engineering and construction of this critical infrastructure.

Early Mains

The first known underground water mains were constructed by the ancient Minoan civilization between 2200 and 1400 BCE. Constructed of terra cotta, these ancient mains supplied water to the Palace of Knossos. In fact, the ancient Minoans were incredibly advanced for their time, as they also had flushing toilets, sewer piping and drainage, and even rainwater harvesting capabilities. Amazingly enough, the water mains of Knossos were over 1,000 years ahead of their time, as there is no historical evidence of any other water mains until the time of the Roman Empire, between 312 BCE and 500 AD.

Remains of part of the famed Roman aqueducts

The Roman Empire saw a time of incredible engineering achievement, including the invention of concrete, the construction of bridges and roads, and of course, the innovation of the famous aqueducts. Using gravity to transport water from the outlying hills to the city, these aqueducts, the longest of which was 57 miles, were an incredible engineering accomplishment — and some still stand today. During the early years of the Roman Empire, only the very wealthiest of Romans had water piped directly into their homes via rudimentary water mains, which were constructed of hollowed out logs or drilled stone. Later, water was piped to additional affluent homes via lead pipes. While some argue that the fall of Rome can be attributed to lead poisoning, there is no hard evidence that this theory is true.

Middle Years

Circa 1790 wooden water main from Boston, Massachusetts

Wooden pipes were used in 16th and 17th century Europe, and in 18th and 19th century Canada and United States. To this day, wooden pipes are occasionally unearthed during construction events in Boston, Massachusetts. Wooden pipes did present some problems in that they tended to attract insects and to rot. Also, they imparted a distinct woody flavor to the water.

In the 1800s, lead pipes came into popularity due to their durability and low cost. However, it was eventually recognized that lead water mains were causing lead poisoning, and by the 1920s, an increasing number of municipalities were prohibiting the use of lead pipes to convey drinking water. Long before Flint, Michigan, one of the worst lead poisoning disasters took place in Lowell, Massachusetts in the 1890s, where some of the drinking water tested contained 1,300 times the current EPA drinking water standard. Werner Troesken, an economist at the University of Pittsburgh, authored an entire book about widespread lead poisoning in turn of the century America from lead water mains.

Modern Times

Pipe_Crush_Test_corrected_horiz-300x171 — Advanced Condition Assessment for Pipeline Rehabilitation helps determine which pipes in a water distribution system are in need of rehabilitation or replacement.

Because lead pipes were recognized to have negative health effects, cast iron water mains because the popular choice in the early 1900s. In use sporadically since 1455 when Germany laid the first recorded cast iron water main in history, cast iron offered a strong, durable, and safe means by which to convey water. Many municipalities on the east coast of America still have cast iron pipes in place that were laid over a century ago. Since their useful life expectancy is 75-125 years, many of these cast iron mains are nearing the end of their useful life or are overdue for replacement. Unfortunately, universal replacement of these failing mains is impossible due to the sheer volume of outdated mains combined with the shrinking budgets and increased regulations that municipalities are currently facing. Therefore, many municipalities are turning to more methodical means of determining which mains should be replaced, such as Advanced Condition Assessment for Pipeline Rehabilitation, which determines the amount of useful life left in a main, and Capital Efficiency Plans™, which identify areas of water systems most in need of rehabilitation, repair, or replacement. Systematically determining utilities’ most critical needs enables efficient use of their limited infrastructure dollars.

Ductile iron main is the material of choice today; shown, Milford Water Company water main install; design, construction administration, and resident observation by Tata & Howard

One of the most important modern innovations in water supply is the development of ductile iron in 1948. First used commercially in 1955, ductile iron main is still used today and boasts the longevity of cast iron pipe with the additional benefits of increased flexibility and strength. In addition to ductile iron, modern day water mains are also constructed from polyvinyl chloride (PVC) plastic pipe.

Looking Ahead

Many advances have been made in the conveyance of water since the early days of the Minoans, with several major innovations occurring during the last century. Building on historical knowledge as well as an ever increasing understanding of water chemistry, toxicology, and engineering, water distribution methodology is likely to continue to evolve in ways that will ensure our water is safe, clean, and abundant for future generations.

World Environment Day 2016

Our world is an amazing place and since 1973, we have dedicated June 5^th to celebrate and acknowledge our beautiful planet. The main focus of this day is to raise awareness of the importance of a healthy and green environment. Air pollution, poor water quality, and unsustainable practices with farming and consumption are just some of the issues we see everyday in the news and other media. As individuals who call Earth home, it is up to us to solve the environmental issues which we hear about all too often. Through simple and effective actions, we can all join the race to make the world a better place. Below are some unique and efficient ways to make our lives eco-friendly as we prepare to celebrate World Environment Day.

Get Involved!

As World Environment Day approaches, it is important to get outside and participate in saving our planet. Tata & Howard took initiative in the 17^th annual Charles River Earth Day Cleanup in Dedham, Massachusetts. Volunteers from the company, along with 3,000 others, picked up trash along the Charles River and made a positive impact on our local environment. Everyone is encouraged to volunteer and get involved in their local communities. Visit https://www.volunteercleanup.org for local volunteering opportunities and meet some great people along the way.

Say Bye to the Bottled Water

Keeping ourselves hydrated is one of the healthiest things we can do for ourselves, but choosing bottled water may cost the environment far more than it does our wallets. Each year, 17 million gallons of oil are used in the production of bottled water. With a gallon of bottled water costing four times more than a gallon of gasoline, it is worth the thought to give tap water a chance. Here at Tata & Howard, we recognize that carrying and refilling our own water bottles with tap water is an important step in saving the environment. Drinking tap water keeps our water dollars local so that our communities can fund water improvement projects and other important water initiatives. Only one percent of Earth’s freshwater is safe for human consumption so its up to us to keep it clean and use it efficiently. For more information on reasons to choose tap water over bottled water, see the downloadable infographic below.

Be Mindful of Food Waste

The annual amount of food waste in the US is enough to feed one billion hungry people in the world. This food waste often ends up in landfills packed tight and covered in trash. Although most food is biodegradable, it does not biodegrade when it is piled with trash and other non biodegradable substances. Therefore, if biodegradable material is sent to a landfill, it becomes part of the problem. The best way to avoid this is to be mindful of the food we buy and consume, and to try to change our buying habits so that we waste less food. When we do need to dispose of food, the best way to do so is by composting. Composting is an excellent way to recycle unused food scraps back into a healthy environment in a controlled way. Some communities have local composting programs but it can also be done at home, even indoors.

Lack of understanding about expiration dates is also a large contributing factor to food waste in the US. Expiration dates refer to a product’s quality, not safety. We can help extend the life of perishables by keeping them at the proper storage temperature, and extra food should be donated to food banks BEFORE it reaches expiration, as food banks cannot accept expired food. Tata & Howard practices strong philanthropy by donating both food and money to local food banks to help feed everyone efficiently. On June 5^th, Tata & Howard encourages everyone to go through their pantries and donate to a local organization for people who need it. Not only will it help save our environment, but will also help the local people in our own communities.

Come Together and Travel Smart

For many people, riding a bicycle or walking to work may be impossible, but there are other excellent ways we can reduce our negative impact on the environment and get where we need to go. Carpooling is a great option. Coworkers who ride to work or lunch together not only help the environment, they also enjoy quality time which leads to team building and a more positive work environment. On our off time, it makes sense to combine all of our necessary errands into one trip. Taking one big trip to get groceries, dry cleaning, and drugstore items can greatly decrease our gas emissions that pollute the air and water in the environment. Americans in recent years have begun to drive less and use other means of public transportation or physical exercise. This trend is exactly what we need to better our planet. On World Environment Day, Tata & Howard encourages everyone to practice eco-friendly transportation. Even if it is only for one day, it will make a difference.

What to Take Away

Our world is awesome but it is not perfect. Our actions of pollution and unsustainable practices are the main contributors to the very real problems that we are currently facing. Actions taken today do make a difference and the more people we can get on board to help the better. On this World Environment Day, let’s all take time to lend a helping hand to our planet. It is up to us as individuals to take action and better our environment. Taking small steps and making an effort to improve the world in which we live is important not only on World Environment Day, but every day. Even if it is a small step, it is still a step in the right direction.

Happy World Environment Day!

National Dam Safety Awareness Day

There are over 87,000 dams in the United States. With one-third of those dams posing a serious threat to people’s lives and property if they fail, dam safety is nothing to ignore. Dams are a critical part of our infrastructure providing flood protection, water supply, hydropower, irrigation, and recreation. Although dam safety may not seem to be a big concern, dam failure can affect people for miles and miles, with sometimes fatal results. National Dam Safety Awareness Day is a day to acknowledge the progress we have made in making our dams safe structures and the continuous progress we still have yet to make.

Damage caused by Lake Delhi Dam failure in Iowa, July 27, 2010

As our population keeps growing, our dams are getting older and some are even deteriorating. A dam can fail within hours of the first signs of breeching. Dam safety is a shared responsibility. Dam owners, engineers, community planners, along with federal and state leaders all have important roles in keeping dams running efficiently and safely.

The National Dam Safety Program (NDSP), led by FEMA, has been working for 30 years to keep Americans safe from dam failures. The NDSP assists states in establishing and maintaining dam safety programs along with providing technical training to state and federal dam safety staff. Their support for research and development has greatly helped raise awareness about improper dam safety along with lessening the impact on a community if a dam were to fail.

Why Dams Fail

One of the most frequent ways dams fail is overtopping. Overtopping is a strong indicator of an unsafe dam. This can happen due to a number of reasons but typically it is from inadequate spillway design, debris blockage, or settlement of the dam crest. Overtopping accounts for about 34% of all dam failures in the United States and can also lead to erosion of the downstream face of the dam. Without proper maintenance of the downstream face, the dam is at a heightened risk of failure. Wind and other harsh weather conditions can cause waves to erode the upstream face which can make the dam unsafe during heavy rainfall or flash floods.

Missouri River Flood: Breeching of the levee at mile 550 in Aitchison County, June 19, 2011

Other important factors that can cause dam failure are seepage and foundation defects. These defects account for about 30% of dam failures in the US, typically due to slide failure. If seepage or other factors weaken the soil supporting a dam, the overall strength of the dam greatly diminishes, creating the potential for a landslide-like affect.

Improper construction measures such as insufficient soil testing also contribute to dam failures. When permeable cavities or course gravel are present in dam foundations, seepage is a big concern because it erodes the soil at a fast rate. This often results in the dam settling or sinking which causes failure. A dam can fail by water passing under, over, through, or around it. Every dam should be properly connected to the ground and constructed using the best materials and methods to meet current design and construction standards.

How to Prevent Failures

When constructing and maintaining a dam, taking the proper engineering steps is vital. For example, completing sufficient soil tests prior to construction helps ensure that the dam will be adequately supported. The soil on the actual site should be examined before any detailed planning is put into place. It is also important to confirm the existence of impervious clay to seal the excavation and form the core of the bank. Failures can be prevented if the contractor is aware of any soil limitations at the site.

Dam failures have taken the lives of hundreds of people in recent decades so it is important to hire the right contractors to do the proper work. Nothing can take the place of a reliable and reputable contractor. Having experienced engineers and machine operators greatly reduces the risk of failure. It is important to review every employee’s credentials before starting a job and to always seek professional advice from an engineer when planning and designing a dam. Improper construction and inspection can lead to a weak structure, which can be dangerous and, sometimes, even fatal.

Maintenance and inspection must be routinely completed in order to keep dams safe. If a problem associated with a dam is not addressed in a timely manner, it can become more dangerous as time goes on. Dam inspectors should document every inspection in order to accurately assess needed repairs. While maintaining a dam, vegetation control, erosion repair, and clearing debris from spillways should be a routine practice. A healthy layer of grass can help prevent erosion, and any debris within 25 feet of the dam should be removed. A poorly maintained dam can cost the owner more to repair than a dam which is regularly inspected and checked for needed repairs.

Emergency Action Plans

Damage left behind after the Teton Dam failure, Rexburg, Idaho, 1976

173 dams across the country have failed since 2005 so it is important to know what your community’s Emergency Action Plan (EAP) is if a local dam were to fail. An up-to-date EAP is critical to reduce the risk of lost lives and property damage. A good EAP accomplishes three main goals: identify the area below the dam that would be flooded, establish a line of communication for the dam owner and emergency response, and provide warnings and evacuations to be conducted by local emergency teams. Below are the six essential elements of a successful EAP.

Notification Flowchart. This is to identify who should be notified by whom, and in what priority. This information is crucial for the notification of the persons in charge of taking emergency actions. The flowchart should have detailed information about each position in the chart such as title, office, and multiple ways of contacting that individual. EAPs should include the residents and businesses downstream of the dam that should be notified in case of an emergency. Proper communication and assigned roles can drastically reduce the impacts of a dam failure.
Emergency Detection, Evaluation, and Classification. This ensures that the appropriate course of action is taken based on the urgency of the situation. Having procedures in place to classify an emergency situation properly will better prepare a community to activate their EAP before a catastrophe occurs. Early detection of a potential problem can save hundreds of lives and millions of dollars in property damage.
Responsibilities. When an emergency occurs, everyone should know their role in reacting to the situation. Typically, the dam owner’s responsibilities include developing, maintaining, and implementing the EAP while state and emergency management officials are responsible for warning and evacuation. Without proper assignment of responsibilities, the EAP would be ineffective.
Preparedness. This section outlines actions to be taken before an emergency occurs. Preparedness actions are taken to moderate or minimize the effects of a dam failure and to identify specific responses to be taken in emergencies.
Inundation Maps. An inundation map identifies the areas affected if a dam were to fail. This map is important in identifying a strategy to notify and evacuate areas in danger. These maps graphically display flooded areas and show travel times for wave front and flood peaks at critical locations.
Appendices. This section contains information directly applicable to the actions of the dam owner and the emergency management parties. The appendices provide information that supports the material used to develop the EAP such as maintenance requirements and dam break investigations.

In Conclusion

Dams serve an important role in our nation’s infrastructure. Millions of people in every state rely on dams to bring them benefits such as flood control, water supply, irrigation, recreational areas, and renewable energy. Safe operation and maintenance is important to sustaining these advantages and avoiding disasters which are very often preventable. Dams fail for a number of reasons but the primary source of failure is poor inspection and maintenance, inadequate design, and improper operation. Know your risk when it comes to dam failure in your community. Getting familiar with your community’s EAP and level of risk from a dam failure can greatly help you in an emergency situation. National Dam Safety Awareness Day is an opportunity to raise awareness about our nations deteriorating dams and to take steps in making them safer structures for our community.

Happy National Dam Safety Awareness Day!

Summertime, Beaches, and Water Quality

Memorial Day is the generally accepted start of summer to most New England communities. Pools are opened, grills are wheeled out from storage, flowers are planted, and beaches are officially opened. And while summer is absolutely breathtaking in New England, it is also a time of increased stress on water quality and supply.

Water Quality

Defined by the EPA as a sandy, pebbly, or rocky shore of a body of water, beaches provide recreation for approximately 100 million United States residents over the age of 16 each year. Families flock to beaches during the summer months to enjoy activities such as swimming, surfing, boating, fishing, parasailing, exploring, walking, and sunbathing. Beaches not only include the sandy expanses with boardwalks and cottage rentals along the coastline, but also lake and riverfront areas, ponds, estuaries, and lagoons, some of which are even found in urban areas. Beaches are also an integral part of the the United States economy and provide habitat to many species.

Unfortunately, because of the huge popularity of beaches in the summer, water quality can suffer. Beach closures are common during the summer months, and are a result of pollutants and pathogens entering the water. One of the most common sources of water pollution is human fecal matter from leaky septic systems and sewer overflows. Human waste contains a variety of harmful organisms, including bacteria, viruses, and parasites, that can cause illnesses such as gastroenteritis, hepatitis, and skin infection to humans. Another source of pollution is animal fecal matter from agricultural and stormwater runoff. While runoff contains a number of pollutants including motor oil, pesticides, fertilizers, and trash, arguably the most dangerous and disruptive is animal feces. A single gram of dog feces contains over 23 million parvovirus bacteria in addition to whipworms, hookworms, roundworms, threadworms, giardia, and coccidian. These pathogens and parasites enter waterways through runoff and can have detrimental effects on waterways, aquatic life, and humans.

algal-bloom-300x225 — Harmful algal blooms are toxic to marine life Image: U.S. Geological Survey, Dr. Jennifer L. Graham

Algal blooms are also more common in summer months. Algal blooms are caused by a variety of sources including warmer temperatures, high light, and increased turbidity, but the most contributive source is nutrients in the water from human and animal waste. Some algal blooms are extremely dangerous and have the potential to sicken or kill humans and animals, while less toxic blooms still cause harm to local economies and the environment. Commonly referred to as red tide, cyanobacteria, or blue-green algae, algal blooms effectively cause dead zones in the water and often require significantly increased treatment costs to remedy.

Water Supply

In addition to water quality issues at beaches, water supply can also be a concern. Since the population at popular vacation spots such as Cape Cod and the Maine beaches increases astronomically in the summer months, so does the demand for water. And not only are these seasonal visitors doing laundry, cooking, and drinking the water — they are also watering their lawns and gardens, which accounts for over half of a household’s total water usage. It is therefore understandable how a small community’s water supply can easily become taxed during the high summer season.

Solutions

Fortunately, there are policies and regulations in place that directly address seasonal water quality and quantity issues. The EPA, along with other governmental agencies, have enacted several laws that aim to protect the quality of our nation’s beaches:

The Clean Water Act
The Clean Water Act, established by the EPA in 1971, establishes the basic structure for regulating discharges of pollutants into the waters of the United States and regulating quality standards for surface waters. Under the Clean Water Act, the following programs specifically address water pollution:

The National Pollutant Discharge Elimination (NPDES) Permit Program
The NPDES program controls water pollution by regulating point sources that discharge pollutants into waters of the United States.

The Pollution Budgeting (TMDL) Program
The TMDL program requires states, territories, and authorized tribes to develop lists of impaired waters, establish priority rankings for waters, and develop Total Maximum Daily Loads (TMDLs). TMDLs related to beaches include pathogens, nutrients, and trash.

The Beaches Environmental Assessment and Coastal Health (BEACH) Act of 2000
The BEACH Act amends the Clean Water Act to better protect public health at our nation’s beaches. The BEACH Act requires EPA to recommend water quality criteria that states, territories, and tribes can adopt into their water quality standards for pathogens and pathogen indicators in coastal recreational waters. The BEACH Act also authorizes grants to states, territories, and eligible Tribes to monitor coastal and Great Lakes beaches and to notify the public when water quality standards are exceeded.

Marine Debris Research, Prevention, and Reduction Act (MDRPRA)
The MDRPRA established programs within the National Oceanic and Atmospheric Administration (NOAA) and the United States Coast Guard (USCG) that identify, determine sources of, assess, reduce, and prevent marine debris. MDRPRA also reactivates the Interagency Marine Debris Coordinating Committee, chaired by NOAA.

The Coastal Zone Management Act
The Coastal Zone Management Act is administered by NOAA, Office of Ocean and Coastal Resource Management (OCRM), and provides for management of the nation’s coastal resources, including the Great Lakes.

The Act to Prevent Pollution from Ships (APPS)
The APPS implements the provisions of Marpol 73/78, the International Convention for the Prevention of Pollution From Ships, 1973 as modified by the Protocol of 1978. (“Marpol” is short for marine pollution.) In 1987, APPS was amended by the Marine Plastic Pollution Research and Control Act. The MPPRCA requires EPA and National Oceanic and Atmospheric Administration (NOAA) to study the effects of improper disposal of plastics on the environment and methods to reduce or eliminate such adverse effects. MPPRCA also requires EPA, NOAA, and the U.S. Coast Guard (USCG) to evaluate the use of volunteer groups in monitoring floatable debris.

Shore Protection Act (SPA)
The SPA is applicable to transportation of municipal and commercial wastes in coastal waters. The SPA aims to minimize debris from being deposited into coastal waters from inadequate waste handling procedures by waste transporting vessels. EPA, in consultation with the Coast Guard, is responsible for developing regulations under the SPA.

Marine Protection, Research, and Sanctuaries Act (MPRSA)
The MPRSA, also called the Ocean Dumping Act, generally prohibits the following:

Transportation of material from the United States for the purpose of ocean dumping;
Transportation of material from anywhere for the purpose of ocean dumping by U.S. agencies or U.S.-flagged vessels; and
Dumping of material transported from outside the United States into the U.S. territorial sea.

In addition to the numerous governmental regulations protecting water quality and our nation’s beaches, local communities also implement policies that specifically aim to address water supply issues. Some of these include the following:

Outdoor water restrictions and bans: Many communities implement water bans in the summer that severely limit or prohibit outdoor watering.
Public education: Many summer communities implement public outreach that includes requests for voluntary conservation.
Leak detection and repair: Because water loss is such a serious issue across the United States, many communities are actively implementing leak detection and repair policies. Repairing older infrastructure typically has an exponential return on investment and also serves as a means of public education, with repair crews in the street garnering local media attention.

In Conclusion

Beaches are one of the most traditional and enjoyable means of summer entertainment for families and individuals, and they provide a plethora of recreational activities for all ages. Protecting our beaches and recreational waters is imperative to the health of our nation’s citizens and economy, and we are fortunate that our nation’s governmental agencies and local communities proactively work to maintain the health of our waters. We as individuals can also help to protect our beaches and waterways by reducing our personal water consumption, cleaning up after our pets, and being mindful of pesticide and fertilizer usage. Together, we can assure that present and future generations are able to enjoy our nation’s beautiful beaches.

Surf’s up!

Infrastructure Week 2016 — #InfrastructureMatters

It is scary to realize how complacent our country has become in accepting crumbling infrastructure as the norm. Our international competitors are investing more in high speed rail, modern airports, and bigger shipping ports, while just about every few months, some kind of preventable catastrophic infrastructure event happens in America. Yet our leaders are still not spurred into taking decisive action.

Infrastructure matters. It matters, in big ways and in small, to our country, our economy, our quality of life, our safety, and our communities. Roads, bridges, rails, ports, airports, pipes, the power grid, and broadband — infrastructure matters to companies that manufacture and ship goods. It matters to our daily commutes and our summer vacations. Infrastructure determines if we can drink water straight from our taps and flush our toilets or do our laundry. It brings electricity in to our homes. Ultimately, infrastructure matters to every aspect of our daily lives.

That is why Tata & Howard has teamed up with hundreds of other groups around the country to participate in Infrastructure Week 2016. We’re raising awareness about the need to invest in infrastructure, which is the backbone of our economy, locally and nationally.

Every year America fails to adequately invest in our infrastructure, the United States becomes less competitive, our economy grows more slowly, and families and businesses lose valuable time and money. The goods we manufacture cost more when they get stuck on congested highways, rerouted around structurally deficient bridges, and stranded at outdated ports. Continued reliance on World War II era technology and airports that lack sufficient capacity cause U.S. consumers to skip travel, costing the economy tens of billions of dollars each year.

Particularly in the northeast, water and wastewater infrastructure has reached the end of its useful life. A water main breaks every two minutes, and we have seen the tragedy that can come from utilizing outdated technology, such as lead pipes in Flint, Michigan. And, our failure to invest in infrastructure ripples throughout the economy: for every $1 invested in infrastructure, $2 in output is created – putting our friends and neighbors to work.

Decades of underfunding and deferred maintenance have pushed our country to the brink of a national infrastructure crisis. And we have begun to accept preventable tragedies as normal, when they should in fact be entirely unacceptable: fatal mass transit accidents; deadly, poisonous drinking water; sickening gas leaks; levee-breaking floods; deadly pipeline bursts; and rivers contaminated with raw sewage. America’s poorly-funded infrastructure and transportation systems can be more than just inconvenient; they can be harmful to our health and safety. Importantly, all of these tragedies are preventable with adequate investment – they are not merely unfortunate accidents we must endure.

Every dollar we invest in infrastructure is an investment in our neighborhoods and our future. Because our roads are in poor condition and littered with potholes, U.S. drivers pay more than $500 in avoidable vehicle repairs and operating costs each year. In Connecticut, the areas of New Haven, Bridgeport, and Stamford have had 45% of their roadways rated “poor” by TRIP, a Washington, D.C.-based national transportation research group. Instead of wasting over 40 hours each year stuck in traffic jams, we could spend that time being productive.

Americans deserve a 21^st century transportation network; modern aviation systems; safe, clean, reliable water and wastewater service; broadband access in every community; and, a freight network and ports that can keep pace in the global economy. To grow our economy, keep Americans safe, and maintain strong communities, we need all levels of government and the private sector to work together to prioritize the rebuilding of our nation’s infrastructure.

During Infrastructure Week, groups are coming together to recognize progress and leadership at the federal, state, and local levels – and there is much to celebrate. For example, communities throughout New England have been proactive in lead service line replacement, and the Massachusetts Water Resources Authority (MWRA) announced in March that $100 million in interest-free loans would be made available to its member water communities to fully replace lead service lines.

But our work is nowhere near complete. As we look to 2016 and beyond, closing our country’s trillion-dollar infrastructure investment gap demands a strong federal partner in funding large and transformative projects. We are going to need real collaboration between the public and private sectors to identify and implement innovative solutions. And leaders at all levels are going to need to finally wake up and commit to building a long-term, sustainable plan to invest in America’s infrastructure. There is too much at stake to fail at any of this. Infrastructure matters.

A History of Dams: From Ancient Times to Today

A dam is a human-made structure that is primarily used to hold back water. Dams are constructed for many purposes, including reservoir creation, flood prevention, irrigation, and hydroelectric power. Today, there are almost 50,000 large dams in use worldwide. The United States has the second largest number of dams in the world at 5,500, and China has the most with a whopping 19,000. The United States has 50 major dams – the most in the world. But before we had the Hoover Dam or any of the other major dams of today, our ancestors had to learn about dam engineering, and some of that was done through trial and error.

The World’s First Dam

The first known dam to be built is the Jawa Dam, which is actually the largest in a series of dams that are all part of one reservoir system. Located in modern-day Jordan, the Jawa Dam was originally constructed around 3,000 BCE in what was then Mesopotamia. Surprisingly, the Jawa Dam was actually an architectural feat of the times. While most ancient dams were simple gravity dams constructed of gravel and masonry, the Jawa Dam was reinforced with rock fill behind the upstream wall in order to protect the wall from water pressure breach. This safety feature was incredibly innovative for this time period. Unfortunately, the reinforced design was forgotten after the Jawa Dam and was not actually “reinvented” until modern times. The Jawa Dam site is arguably the most important archaeological site in the history of large-scale water projects, and the dam itself was so well designed and constructed that the ancient structure stood until just a few years ago, when it was partially ruined due to physical intervention. In its prime, the Jawa Dam was 15 feet tall, 80 feet long, with a base of 15 feet. It created the Jawa Reservoir that had a capacity of 1.1 million cubic feet.

Ancient Dams

Remains of the poorly designed Sadd el-Kafara

Subsequent ancient dams were built by several cultures with varying rates of success. Approximately 400 years after the construction of the highly successful Jawa Dam, Egyptians built the Sadd el-Kafara, or Dam of the Pagans, most likely to supply water to the local quarries outside of Cairo rather than for irrigation, since the flooding Nile would have supplied plenty of water to the farmers. After ten years of construction, the masonry dam was 37 feet tall, 348 feet long, with a base of 265 feet, contained over 100,000 tons of gravel and stone, and had a limestone cover to resist erosion. Unfortunately, as it was nearing completion, it failed. Due to poor design and lack of a spillway, the dam washed away during a heavy rainfall and was never repaired or completed. Discouraged by the failure of this massive project, ancient Egyptians were dissuaded from constructing other dams until many years later.

The Romans, highly regarded for their advances in hydraulic engineering, were prolific in dam construction during the height of the empire. In addition to the vast network of aqueducts, the Romans built a plethora of gravity dams, most notably the Subiaco Dams, which were constructed around 60 AD to create a pleasure lake for Emperor Nero. The Subiaco Dams were a series of three gravity dams on the Aniene River in Subiaco, Italy, the largest of which stood 165 feet tall and held the honor of being the tallest dam in the world until its destruction in 1305, historically attributed to two careless monks. The Romans also constructed the world’s first arch dam in the Roman province of Gallia Narbonensis, now modern-day southwest France, in the 1^st century BCE. The remains of the Glanum Dam, the first recorded true arch dam in history, were discovered in 1763. Unfortunately, a modern arched gravity dam replaced the ancient structure in 1891, and all remnants of the Glanum Dam were lost. The Romans were also responsible for constructing the world’s first buttress dams, although they tended to fail due to their too-thin construction. One third of all dams on the Iberian Peninsula were buttress dams.

The Cornalvo Dam, a Roman gravity dam in built in the 1st or 2nd century AD, still supplies water to the people of Meriden, Spain.

Asian cultures also contributed to dam engineering. As early as 400 BCE, Asians built earthen embankments dams to store water for the cities of Ceylon, or modern-day Sri Lanka. In the 5^th century AD, the Sinhalese built several dams to form reservoirs to catch the monsoon rains for their intricate irrigation system, and many of these reservoirs are still in use today. Around the 12^th century AD, about 4,000 dams were built by an egotistical Sinhalese ruler, King Parakrama Babu. While these structures were gargantuan for the time, such as one dam that stretched for almost nine miles, they are not considered to have any true engineering significance, as they did not supply water to the villages. Built to massage the king’s giant ego, these enormous dams were monuments rather than functional structures.

Japan and India also contributed to early dam engineering, with much success. In fact, five of the ten oldest dams still in use are located in these two countries. The oldest operational dam in the world, the Lake Homs Dam in Syria, was built around 1300. The masonry gravity dam is over one mile long, 23 feet high, and creates Lake Homs, which still supplies water to the people of Homs today.

Middle Ages

During the dark ages, dam construction came to a near halt, resuming around the 15^th century AD. During this time, no major contributions to dam engineering were made, and the majority of the dams constructed in Europe, where rainfall is plentiful and regular, were modest structures. It wasn’t until the 1850s, when civil engineering professor William John Macquorn Rankine at Glasgow University demonstrated a better understanding of earth stability and structural performance, that dam engineering improved. In fact, Rankine’s work was so innovative, it contributed to the acceptance of civil engineering as a valid university subject and improved the status of civil engineers. Since Rankine, geological, hydrological, and structural scientific contributions have been extensive, and the understanding of dam engineering has improved significantly as a result.

Modern Times

Major advances in concrete dam design were made from 1853 to 1910 by British and French engineers. During this time, understanding of the relationship between the precise weight and profile of gravity dams and the horizontal thrust of water increased extensively. In 1910, further advances were made as engineers began to take a more three dimensional approach to dam engineering, examining the effect of individual stresses and deflections on multiple points rather than on the structure as a whole. By recognizing the complexity of the structure and understanding its interconnectedness, engineers were able to make exponential advances in dam engineering. As a result of this enhanced understanding, model techniques were implemented at this time. Originally built in rubber, plaster, plasticine, or concrete, modelling is now also done digitally, allowing multi-faceted and comprehensive testing and examination of structural stability.

The world’s largest and most complex dams have all been built within the last century, due to engineering as well as technological advances. In addition to supplying water and controlling flooding, modern dams are often constructed to provide hydroelectric power. The Hoover Dam, a concrete arch-gravity dam constructed in the Black Canyon of the Colorado River in 1936, is a prime example of the major advances made in dam engineering. The massive dam, which impounds Lake Mead, stands a whopping 726 feet tall and has a reservoir capacity of 28,537,000 acre feet. It also provides four billion kilowatt-hours of hydroelectric power — enough to supply the private and public electrical needs of over eight million people in Nevada, Arizona, and California— each year. Once the tallest dam in the world, the Hoover Dam lost its title to Switzerland’s 820-foot-tall Mauvoisin Dam in 1957. In the United States, California’s Oroville Dam is now the tallest at 770 feet.

Looking Forward

dam-removal-300x182 — Workers dismantle the Savage Rapids Dam on the Rogue River in Oregon. (Photo courtesy of Oregon State University)

While dams have been being constructed for over 5,000 years, the last 100 years have seen the most significant contributions in dam engineering. With the increased understanding of earth sciences comes the realization that some dams are actually detrimental to the earth’s ecology. Because of this knowledge, over 900 dams in the United States have been removed since 1990. Also, the understanding of dam safety has made significant strides over the last 100 years, and dam safety programs have been implemented in 49 of the 50 US states — only Alabama has no dam safety program. Of those 49 states, all but eight also require that all significant and high hazard dams require Emergency Action Plans (EAPs).

With the tens of thousands of existing large dams throughout the world, and the ever-increasing demand for water and power, dams will continue to make a significant impact on modern day life. And, as is evidenced by history, dam engineering will continue to evolve as additional innovations, discoveries, and technological advances are made.

Category: The T&H Blog

Water Crisis in the United States, Part 2: Crumbling Infrastructure

Water Crisis in the United States, Part 1: Navajo Nation

Meeting Wastewater Utilities’ Needs Through Capital Efficiency

A Roadmap to Massachusetts MS4 Stormwater Compliance

Water Mains — Then and Now

World Environment Day 2016

National Dam Safety Awareness Day

Summertime, Beaches, and Water Quality

Infrastructure Week 2016 — #InfrastructureMatters

A History of Dams: From Ancient Times to Today

Let's stay in touch.

Get the latest news, blogs, and insights conveniently in your inbox.