Green and Convenient: The Future of Transportation with Electric Bike Sharing

 Electric bike sharing is an innovative and eco-friendly mode of transportation that is gaining popularity around the world. It is a system where bikes are made available for public use at designated locations, and users can rent them for a certain period of time using a mobile app or a smart card. Electric bike sharing offers many benefits, including reduced traffic congestion, improved air quality, and increased physical activity.

One of the trends in electric bike sharing is the use of electric bikes with longer battery life and faster charging times. This allows bikes to be used for longer periods of time without needing to be recharged, making them more convenient and practical for users. Additionally, some electric bike sharing programs are now offering bikes with cargo capabilities, making them suitable for small businesses and delivery services.

Another trend is the integration of electric bike sharing with public transportation systems. This allows users to seamlessly switch between different modes of transportation, making it easier and more convenient to get around cities. Some electric bike sharing programs are also partnering with ride-hailing services, allowing users to book an electric bike as part of their ride.

Furthermore, many electric bike sharing programs are incorporating sustainability practices into their operations. This includes the use of renewable energy sources to power charging stations, the use of eco-friendly materials for bike components, and the implementation of recycling and waste reduction practices.

The adoption of electric bike sharing is expected to continue to grow as cities look for sustainable transportation alternatives and people seek out eco-friendly ways to get around. Many companies are also investing in the development of electric bike sharing technology, including more advanced battery technology and better bike tracking and monitoring systems.

In conclusion, electric bike sharing offers a sustainable and convenient alternative to traditional modes of transportation. As technology continues to improve and sustainability becomes increasingly important, it is likely that the adoption of electric bike sharing will continue to grow, offering benefits for both individuals and the environment.

The Rise of Sustainable Home Cleaning Products: Trends and Innovations for a Cleaner Future

Sustainable home cleaning products are becoming increasingly popular as people look for ways to reduce their environmental impact and live more sustainably. These products are made from natural and non-toxic ingredients that are safe for both the environment and human health. They are also biodegradable, which means they break down easily and do not harm the environment.

Sustainable home cleaning products can be used to clean a wide range of surfaces, including floors, countertops, and windows. They are available in a variety of formats, including sprays, wipes, and concentrated liquids that can be diluted with water. Many sustainable home cleaning products are also cruelty-free and vegan, which means they have not been tested on animals and do not contain animal-derived ingredients.

One trend in sustainable home cleaning products is the use of refillable and reusable containers. Instead of purchasing a new bottle of cleaning product every time, consumers can purchase a refill that can be used to top up their existing bottle. This reduces waste and helps to minimize the environmental impact of the product.

Another trend is the use of compostable and biodegradable packaging. Sustainable home cleaning products are often packaged in materials that are environmentally friendly and can be easily disposed of. This reduces waste and helps to minimize the environmental impact of the product.

Additionally, sustainable home cleaning products are often made from locally sourced ingredients, which helps to support local communities and reduce the carbon footprint associated with transportation. Many sustainable home cleaning product manufacturers also prioritize sustainable and ethical practices in their manufacturing processes.

The demand for sustainable home cleaning products is expected to continue to grow as people become more conscious of their environmental impact and seek out products that align with their values. As a result, many traditional cleaning product manufacturers are also beginning to introduce sustainable and eco-friendly products into their product lines.

In conclusion, sustainable home cleaning products offer a range of benefits for consumers and the environment. With the trend towards sustainable living and environmental consciousness, it is likely that the demand for these products will continue to grow in the coming years.

Reducing Your Carbon Footprint: The Benefits and Trends of Carbon Offsetting Services

 Carbon offsetting is a service that allows individuals and businesses to reduce their carbon footprint by investing in carbon reduction projects. These projects may include renewable energy initiatives, forest conservation, and energy efficiency improvements. The goal of carbon offsetting is to reduce greenhouse gas emissions in one location to balance out emissions produced elsewhere, effectively neutralizing the carbon impact.

Carbon offsetting services provide a way for individuals and businesses to take responsibility for their carbon footprint and support initiatives that contribute to a more sustainable future. The process typically involves calculating the carbon footprint of a person or business, identifying the amount of carbon emissions that need to be offset, and investing in carbon reduction projects that are equivalent to that amount.

Carbon offsetting services are becoming increasingly popular as more individuals and businesses seek to reduce their carbon footprint and become more environmentally responsible. In fact, the global carbon offset market was valued at USD 8.6 billion in 2020 and is expected to grow at a compound annual growth rate of 14.1% from 2021 to 2028.

The trend of carbon offsetting services is also reflected in the rise of corporate social responsibility initiatives, which encourage businesses to take a more active role in mitigating their environmental impact. Many companies are now committing to carbon neutrality targets, with carbon offsetting playing a key role in achieving these goals.

Furthermore, carbon offsetting services are evolving to become more accessible and transparent. Some providers are now offering online calculators that allow individuals and businesses to estimate their carbon footprint and purchase carbon offsets directly. Others are using blockchain technology to provide a more secure and transparent way to track carbon offsets, ensuring that investments are going towards verified carbon reduction projects.

Overall, the trend of carbon offsetting services reflects a growing awareness and urgency around the need to address climate change, and the role that individuals and businesses can play in supporting a more sustainable future.

As the world continues to grapple with the impacts of climate change, individuals and businesses alike are seeking ways to reduce their carbon footprint and support a more sustainable future. One solution that has gained traction in recent years is carbon offsetting, a service that allows individuals and businesses to invest in carbon reduction projects to neutralize their carbon impact.

Carbon offsetting services have numerous benefits, both for the environment and for individuals and businesses looking to reduce their carbon footprint. By investing in carbon reduction projects, individuals and businesses can help support initiatives that reduce greenhouse gas emissions, promote renewable energy, and conserve natural resources. This not only helps to mitigate climate change, but also supports the development of a more sustainable economy.

Moreover, carbon offsetting can be a valuable tool for individuals and businesses looking to achieve carbon neutrality or other sustainability targets. Many companies have set ambitious carbon reduction goals, and carbon offsetting can play an important role in achieving these targets. By investing in carbon reduction projects, businesses can not only reduce their carbon footprint, but also demonstrate their commitment to sustainability to customers, investors, and other stakeholders.

The trend of carbon offsetting services is also reflected in the growing demand for corporate social responsibility (CSR) initiatives. Many businesses are now taking a more active role in mitigating their environmental impact and supporting sustainable development. By investing in carbon reduction projects, businesses can not only meet their CSR objectives, but also improve their brand reputation and enhance customer loyalty.

Moreover, carbon offsetting services are becoming increasingly accessible and transparent, making it easier for individuals and businesses to invest in verified and high-quality carbon reduction projects. Online calculators and blockchain technology are two examples of tools that are making carbon offsetting more accessible and transparent. These tools allow individuals and businesses to estimate their carbon footprint, purchase carbon offsets directly, and track the impact of their investments.

In conclusion, carbon offsetting services offer numerous benefits for individuals and businesses looking to reduce their carbon footprint and support sustainable development. The trend of carbon offsetting is expected to continue to grow in the coming years, as more individuals and businesses seek to take responsibility for their carbon impact and contribute to a more sustainable future.

Going Zero-Waste: The Rise of Eco-Friendly Zero-Waste Grocery Stores

 Zero-Waste Grocery Stores: Sustainable Shopping for a Greener Future

A zero-waste grocery store is a retail store that sells groceries, household items, and personal care products without using single-use packaging. The aim of a zero-waste grocery store is to reduce waste by encouraging customers to bring their own reusable containers to fill with bulk items such as grains, pasta, nuts, and spices. The store also provides reusable alternatives to common single-use items such as bags, straws, and utensils.

In a zero-waste grocery store, products are sold in bulk, typically stored in dispensers or bins. Customers bring their own containers such as jars, bags, or containers made of durable materials such as stainless steel or glass. The store can also offer reusable containers for customers who forget to bring their own.

In addition to bulk items, zero-waste grocery stores may also sell fresh produce, dairy products, and meat. These products are often sold without packaging or wrapped in biodegradable or compostable materials.

Zero-waste grocery stores also prioritize eco-friendly practices in their daily operations. For example, they may use renewable energy sources, compost organic waste, and minimize water use.

The concept of zero-waste grocery stores has gained popularity in recent years as consumers become more conscious of the environmental impact of single-use packaging. By reducing waste, zero-waste grocery stores contribute to a more sustainable and eco-friendly future.

Zero-Waste Grocery Stores: Growing Trends in the Market and Business for Sustainable Shopping

The trend of zero-waste grocery stores is growing as consumers become more environmentally conscious and demand more sustainable alternatives to traditional grocery stores. Here are some of the trends related to zero-waste grocery stores:

1. Expansion of zero-waste grocery chains: Zero-waste grocery stores are expanding beyond small independent stores and are now being established as chains. This provides consumers with more accessibility to zero-waste shopping options.

2. Collaboration with local producers: Zero-waste grocery stores are increasingly collaborating with local farmers and producers to offer fresh and locally-sourced products, reducing transportation emissions and supporting local economies.

3. Digitalization and online ordering: Some zero-waste grocery stores are introducing online ordering and delivery services to cater to a wider range of consumers who may not have easy access to physical stores.

4. In-store education and events: Zero-waste grocery stores often hold educational events and workshops to promote sustainable living practices, encouraging customers to make sustainable choices beyond just their grocery shopping.

5. Partnerships with other businesses: Zero-waste grocery stores are partnering with other businesses, such as cafes or restaurants, to promote a more sustainable and circular economy. For example, cafes may use leftover food from the grocery store to create meals, reducing food waste.

These trends reflect a growing demand for sustainable and eco-friendly options in the grocery industry, and the zero-waste grocery store concept is an innovative response to this demand. The trend is expected to continue as more consumers prioritize sustainability in their purchasing decisions.

Sustainable Fashion Brands: Ethical and Eco-Friendly Clothing for a Better Future

 

A sustainable fashion brand is a company that creates clothing and accessories using environmentally friendly and socially responsible practices. The fashion industry is known for being one of the most polluting industries in the world, with a significant impact on the environment and people's lives. Sustainable fashion brands aim to address this issue by using sustainable materials, minimizing waste, and supporting ethical production practices.

Sustainable fashion brands use a variety of eco-friendly materials such as organic cotton, bamboo, hemp, and recycled fabrics. They also focus on creating timeless, high-quality pieces that are designed to last for years, rather than following the fast fashion trend of producing cheap and disposable clothing.

In addition to using sustainable materials, sustainable fashion brands also focus on reducing waste in their production processes. They may use recycled materials in their packaging, or use biodegradable and compostable materials to reduce their impact on the environment.

Sustainable fashion brands also prioritize ethical production practices. This includes ensuring fair labor practices and working conditions for workers throughout the supply chain, from the farmers who grow the materials to the workers who manufacture the clothing.

By supporting sustainable fashion brands, consumers can make a positive impact on the environment and society while also enjoying stylish and high-quality clothing.

5 Sustainable Fashion Brands Trend

The trend of sustainable fashion brands has been steadily growing in recent years as more consumers become aware of the environmental and social impact of the fashion industry. Here are some of the sustainable fashion brand trends:

1. Use of sustainable materials: Sustainable fashion brands are increasingly using eco-friendly and sustainable materials such as organic cotton, recycled polyester, hemp, and bamboo.

2. Circular fashion: The circular fashion model aims to create a closed-loop system where materials are reused and recycled, reducing waste and environmental impact. Sustainable fashion brands are adopting this model by using recycled materials and offering repair and recycling services.

3. Transparency and accountability: Sustainable fashion brands are transparent about their production processes, materials, and labor practices. They are also accountable for their impact on the environment and society, and often work with third-party organizations to verify their sustainability claims.

4. Slow fashion: Slow fashion is a movement that promotes quality over quantity, encouraging consumers to invest in high-quality and long-lasting clothing rather than fast fashion trends. Sustainable fashion brands focus on creating timeless pieces that are designed to last, reducing the need for frequent replacements.

5. Fair labor practices: Sustainable fashion brands prioritize fair labor practices and work with manufacturers who provide safe working conditions and fair wages for workers throughout the supply chain.

These trends reflect a growing consumer demand for sustainable and ethical fashion, and the fashion industry's response to the need for more environmentally and socially responsible practices.

Top 10 Sustainable Business Ideas for Eco-Friendly Entrepreneurs

 

1. Sustainable fashion brand: Launch a fashion brand that uses only sustainable and eco-friendly materials such as organic cotton, bamboo, and recycled fabrics. The brand can focus on creating timeless, high-quality clothing pieces that are designed to last for years.

2. Zero-waste grocery store: Create a grocery store that produces zero waste by using only reusable packaging for products. Customers can bring their own containers to fill up with bulk items such as grains, pasta, and spices. The store can also offer reusable alternatives to common single-use items such as straws and utensils.

3. Carbon offsetting service: Offer a service that helps businesses and individuals offset their carbon footprint by investing in renewable energy projects or supporting reforestation efforts.

4. Sustainable home cleaning products: Develop a line of eco-friendly and non-toxic cleaning products for homes that are safe for people and the environment. The products can be packaged in refillable containers to reduce waste.

5. Electric bike sharing: Launch an electric bike-sharing service that allows people to rent electric bikes for short periods of time to get around the city. The bikes can be powered by renewable energy sources such as solar or wind power.

6. Sustainable food truck: Start a food truck that serves organic and locally sourced food that is prepared using sustainable cooking practices. The truck can also use biodegradable and compostable packaging.

7. Renewable energy consulting: Offer consulting services to businesses and individuals who want to transition to renewable energy sources such as solar, wind, and geothermal power.

8. Sustainable tourism: Create a sustainable tourism company that offers eco-friendly travel experiences such as nature walks, wildlife watching, and sustainable accommodations.

9. Vertical farming: Use vertical farming techniques to grow crops in a sustainable and eco-friendly way. The crops can be grown indoors using hydroponic systems and LED lights, which require less water and energy than traditional farming methods.

10. Composting service: Provide a composting service to businesses and households that helps to reduce food waste and create nutrient-rich soil for gardens and farms. The compost can be sold to local farmers and gardeners.

Rethinking the Car

The future is here. If you’ve seen the latest Star Trek movie, which shows the early life of James Kirk, Spock, and the other original crew members of the starship Enterprise, you’ve seen the Aptera. The electric car was featured in the movie as the vehicle driven around the campus of Starfleet Academy.

Believe it or not, these cars—the Aptera 2 series—weren’t designed for a futuristic movie set, but for today’s city streets. And they’ll be available soon. How is this possible? Because of a lot of smart, outside- the-box thinking and a desire to use the least amount of fossil fuel possible.

Despite popular thinking, an all-electric car is not a new idea. In fact, electric cars were some of the earliest automobiles made. The fi rst electric vehicle, a train, was invented in the 1830s. Then, in the 1880s, the fi rst electric car came along. Companies started manufacturing electric cars manufactured for the general public shortly thereafter. They became so popular that more people drove electric cars than gasoline-powered vehicles in Europe and America up until the 1920s, when large amounts of oil were found in the American West and in the Middle East.

These vast new reserves of oil made gasoline-powered cars more economical than electric cars, meaning they cost less to drive. Engineers focused on building gas-powered cars, and electric cars were left in the dust.

However, now that oil is becoming harder to fi nd and getting more expensive, several small companies and even some of the big car manufacturers are working on building an effi cient electric car that is cheap to run.

Problems—including battery weight and size, run time, and the lack of charging stations—have made the large-scale manufacture of all-electric vehicles diffi cult to achieve. That is, until the Aptera came along.

In March 2009 Aptera Motors employees brought the Aptera 2e to Washington, D.C., to protest the car’s exclusion from the Department of Energy’s loan program for fuel-effi cient vehicles. Members of Congress and tourists took the opportunity to ride in the 2e.

THE ULTIMATE GREEN CAR

The Aptera 2 series includes the 2e, an all-electric car, and the 2h, a series hybrid. A series hybrid is a type of vehicle in which power is provided by an electric motor that is assisted by a gasoline-powered generator. When the batteries powering the motor run low on charge, the generator starts and charges the batteries while the vehicle is still in motion.

The 2 indicates the car can carry two passengers. The e stands for “electric” and the h for “hybrid.” The Aptera 2e and 2h are considered to be some of the most fuel-effi cient cars ever made.

Aptera Motors, the company that developed and produces the Aptera, has achieved this energy effi ciency by building the car to be as aerodynamic as possible. This means that the shape of the car enables air to pass easily over its body, causing less friction. The company called the car Aptera, which is Greek for “wingless flight,” because the car “flies” on the ground.

One problem electric-car manufacturers have often had is that the weight of the car requires a lot of battery power. According to Aptera Motors CEO Paul Wilbur, a four-wheeled Aptera would be 34 percent less fuel effi cient than the current three-wheeled design. To carry the extra weight of a four-wheeled model, the car would need a battery 50 percent larger.

Aptera Motors founders Chris Anthony (left) and Steve Fambro stand in front of the Aptera.

The Aptera’s designers even made the wheels themselves more aerodynamic by enclosing them in their own casings. This allows the air to flow over and past them more easily instead of getting caught up in the spokes of the rims. Also, the wheels are low-rolling resistance tires, which reduce the amount of friction the tires generate against the road, resulting in higher energy effi ciency.

In another nod to aerodynamics, the headlights and windshield wipers, which catch a lot of air on normal cars, are set into the surface so that they further reduce drag.

All of these aerodynamic and weight design ideas have allowed the Aptera 2e to achieve an amazing fuel-effi ciency rating of 340 miles per gallon (145 kilometers per liter), according to the company’s estimates. That’s almost seven times the average fuel rating for the Toyota Prius. (Although the 2e doesn’t use gasoline, miles per gallon is still used to compare it with most other cars, which do run on gas.)

The 2e can go 120 miles (193 km) on a single charge, at a cost per mile of 1.5 cents (based on a gas price of $2.67 per gallon). This is far better than every other car on the market today, from the big, bulky 6-cylinder, front-wheel-drive Chevy Equinox SUV (13.4 cents per mile) to the incredibly fuel-effi cient Toyota Prius hybrid (5.36 cents per mile).


What a Drag

According to company founder Steve Fambro, an entire 1,500-pound (680-kilogram) Aptera produces less drag than just the side-view mirror of a pickup truck or Lance Armstrong on his racing bike. This means that the Aptera is extremely aerodynamic.

Engineers can measure how aerodynamic a vehicle is by measuring its drag. The measurement of this drag, or air resistance, acting on a traveling object is called the drag coeffi cient. For example, the Aptera has a drag coeffi cient of 0.15, which is the lowest of any car on the market. In comparison, the Toyota Prius has a drag coeffi cient of 0.25.

The shape of a vehicle is one of the main factors that determine how aerodynamic a car is. Boxier cars have a higher drag coeffi cient, while sleeker, rounded cars have a lower one. Race cars, which are always very slim and low to the ground, are more aerodynamic. This means they produce less drag and can therefore move faster.

Because the teardrop-shaped Aptera glides so smoothly through the air, when the driver’s foot is off the accelerator the car doesn’t jolt to a slower speed as most other cars do. Instead, the Aptera settles into a coast and gradually slows down.

The company’s green philosophy goes beyond fuel effi ciency and emissions. Many of the materials used in the Aptera are ecofriendly. The seat covers and flooring are made from recycled plastic bottles and colored using organic dyes. Even the steering wheel is made from recycled materials. Also, the interior lights use lowenergy light-emitting diodes (LEDs).

The Aptera 2e was one of the fi rst cars to be entered in the Progressive Insurance Automotive X Prize, which is a competition to create supereffi cient vehicles to reduce America’s dependence on oil. The three top winners will share the $10 million prize.


AN IMAGINATIVE IDEA

While stuck in packed Los Angeles traffi c, Aptera Motors cofounder Steve Fambro started thinking about all the wasted fuel and how much better it would be to zip around the city’s highways and streets in a zero-emissions, highly effi cient car. He couldn’t stop thinking about it.

Eventually he contacted a friend of his, a boatbuilder named Chris Anthony, who loved the idea. He brought to the venture his experience with boatbuilding and his knowledge of the unique materials used for boats. That’s where the idea for the Aptera’s lightweight yet extremely strong chassis, or frame, came from. The Aptera’s chassis is made from the same material used to make boats, which can withstand impacts and strong water pressure.

Fambro and Anthony joined forces and approached Idealab, an investment company, for fi nancial support. Idealab’s founder, Bill Gross, was psyched about the idea and invested in the new company, called Aptera Motors.

Fambro and Anthony then assembled a team of engineers and began to make their dream a reality. Work got underway in 2006. Aptera Motors grew, and was almost ready to release its fi rst production models after about four years.

Carbon Adsorption

Adsorption is the process of removing chemicals from a solution by accumulating the chemicals on a solid surface. Engineers refer to this as the transition from an aqueous environment to a solid environment. Large wastewater treatment plants have more than one method for removing hazards from wastewater; adsorption supplements these treatments because of its efficiency and ease of use. Sustainable wastewater treatment plants, small rural plants on a strict budget, and sustainable homes act as ideal places to use adsorption for cleaning wastewater.

Three types of adsorbents, substances that adsorb materials from water, work in treatment: activated carbon, synthetic long-chain compounds called polymers, and silica-based adsorbents. Polymers and silicabased compounds are expensive, but inexpensive activated carbon has been important in wastewater treatment for many years. Activated carbon consists of any material with high carbon content, which is treated to increase its capacity to draw contaminants from water. Also important, activated carbon holds onto the contaminants and does not release them back into the water.

Makers of activated carbon use any of the following high-carbon materials as precursors: almond, coconut, or walnut hulls; wood; bone; or coal. The activation process contains the following two steps: (1) heating the material to 700°F (371°C) to burn off hydrocarbons and make a material called char; and then (2) activating the char by exposing it to steam and carbon dioxide to create a porous structure. The extensive pore system in the carbon greatly increases surface area and thus makes the material much more efficient as an adsorbent. Activated carbon tends to contain the following pore sizes:

1. macropores—greater than 25 nanometers (nm)
2. mesopores—greater than 1 nm and less than 25 nm
3. micropores—less than 1 nm

 Wastewater treatment systems use either of two types of activated carbon: (1) powdered activated carbon (PAC) that contains small particles (less than 0.075 mm diameter), or (2) granular activated carbon (GAC) that contains larger particles of about 0.1–2.4 mm diameter. Smaller particle sizes also increase the adsorbing surface area compared with large particles.

Carbon adsorption works by exposing the solid surface to a flowing liquid. Contaminants drift toward the solid-liquid interface located adjacent to the solid adsorbent. Contaminant molecules diffuse through this static interface and enter the particles’ pores where they attach to sites called available adsorption sites, which are spaces on the adsorbent’s surface that are unclaimed and available to catch and hold onto a contaminant. Because water flows in and around the adsorbent’s pores, the method is often called carbon filtration. A variety of chemical interactions create the force that holds a contaminant on the surface: charge, covalent bonding, hydrogen bonding, or van der Waals forces. Covalent bonds occur when two atoms share electrons, while van der Waals forces develop when adjacent atoms share a weak attraction to each other because of an electromagnetic field.

Carbon adsorption offers an inexpensive and easy-to-maintain water cleaning method for sustainable homes, especially for treating gray water. The carbon can be reactivated once it has filled up with contaminants and no longer has many available adsorption sites remaining. Reactivation uses the same process as that used to activate char, that is, heating. For home systems, homeowners can simply replace the activated carbon filter every six months to a year after installing it rather than reactivate a used filter.

Energy from Wastewater

Sustainable wastewater treatment involves the reuse of the process’s byproducts for the treatment plant’s operations. A typical wastewater treatment plant offers several options for generating energy or carrying out other conservation measures. Carefully planned wastewater treatment can provide the following benefits: (1) the natural flow of water due to gravity can act as an energy source; (2) methane and hydrogen production from anaerobic digestion serve as energy sources for powering the facility; (3) the reactions inside the digester produce heat that can be rerouted to other biological processes; (4) the treatment plant’s gray water may be reused for flushing toilets; and (5) nutrient-rich sludge exiting the digester serves for landscaping the facility’s grounds or may be sent to local farmers. In summary, in sustainable wastewater treatment, everything is used and reused to the maximum.

The wastewater industry resembles other industries today in trying to meet stricter pollution requirements while reducing energy use. Water and wastewater treatment in the United States uses only 2 percent of the country’s total amount of energy, but with concerns over fuel and energy costs the industry faces the need to build more sustainable operations. Electricity needs of wastewater treatment plants vary by the amount of incoming wastewater they treat each day and the concentration of waste in the water.

Sustainable wastewater treatment plants allow water to naturally purify and consume minimal energy for pumping water. Methane gas from the treatment plant’s anaerobic digester can provide some or all of this energy. The Earth purifies the water due to the soil’s ability to remove particles and bind to many organic compounds.

Sustainable practices in wastewater treatment provide some or all of the energy needs for running pumps for the aeration step and other pumps, heating, and lighting. Methane serves as the most efficient energy source for these purposes, helped to a smaller degree by hydrogen gas. Wastewater-to-energy plants recover methane in a three-step process that involves (1) dehydration, (2) gas cooling, and (3) removal of hydrocarbon compounds heavier than methane. This process results in pure methane of natural gas quality. Methane contains a heating value of 55.5 megajoules per kg of material compared with natural gas’s 53.0 MJ/kg. Other fuels do not provide as much energy as methane: gasoline (48.1 MJ/kg); home heating oil (45.5); coal (28.5 MJ/kg); and wood (about 15 MJ/kg). Wastewater-to-energy therefore holds exciting promise for leading the way in new waste-to-energy technologies.

Ecological Wastewater Treatment

Ecological wastewater treatment encompasses three control methods for keeping wastewater from harming the environment: odor control, methane control, and discharge cleanliness. Odors from gases like hydrogen sulfide emitted from anaerobic digestion do not harm human health but make the surroundings unpleasant for neighbors of treatment facilities. Anaerobic digesters help solve most of this problem, and methane collection devices over manure tanks also reduce odors. Methane collection as previously discussed in this chapter is a critical part of ecological wastewater treatment because it can have a meaningful effect on greenhouse gas levels. The third factor, discharge of cleaned water, represents the wastewater industry’s major responsibility and the U.S. Environmental Protection Agency (EPA) enforces strict laws on the quality that treated wastewater must achieve. The government expects treatment plants to keep the amounts of treated wastewater constituents within certain predetermined limits. The following table describes the constituents in wastewater that the EPA monitors to avoid harm to the environment. These constituents must be controlled within the EPA’s acceptable limits whether a treatment

 facility runs traditional wastewater treatment or wastewater-to-energy processes.

 Wastewater treatment methods offer the following advantages: (1) easy to install and use; (2) small energy demand by most methods; and (3) inexpensive, except for ozone disinfection, ultraviolet disinfection, and ion exchange.

Methane—Cow Power

Cattle, meaning dairy cows and beef animals, belong to a diverse group of animals called ruminant animals, or simply ruminants. Ruminants possess a four-part digestive system composed of a stomach similar to a human stomach and three additional chambers that carry out a different digestion than found in the stomach. Ruminants exist on a diet of fibrous plants that require a good deal of chewing to digest. These animals do this by swallowing partially chewed food, regurgitating it, chewing it again to further break up the pieces (called chewing the cud), and then re-swallowing the material. The smaller, chewed pieces move into the other compartments that contain enormous numbers of anaerobic bacteria and protozoa, especially the biggest compartment called the rumen. Rumen microbes degrade fibers into organic acids that the animal relies on for energy. As the microbes work they release methane, which the animal must constantly eliminate by belching or passing along to the large intestines. The methane drifts upward into the atmosphere and mixes with other greenhouse gases.

CO2 receives most of the blame for the crisis of greenhouse gases and global warming, but, in fact, other gases cause much more harm to the environment. Methane contributes about 20 times more to global warming than CO2. The EarthSave environmental organization has calculated that animal agriculture produces 100 million tons (91 million metric tons) of methane a year. Cattle produce about 20 percent of the methane emissions in the United States, and, unlike new methane-reducing technologies for factories and wastewater treatment plants, these cattle must keep producing methane as long as they live.

Environmental scientists have considered two divergent solutions to cattle methane: capturing the methane for energy or altering normal ruminant digestion to produce less methane. Capturing the methane from belching cows presents an understandably difficult task, so engineers have turned their attention to the large amounts of methane that come from cattle manure. Pacific Gas and Electric Company has embarked on a program to capture this “cow power.” Roy Kuga, its vice president of energy supply said, “With nearly 2 million dairy cows in California, there is great potential for the state’s agriculture and power sectors to work together to address the challenges of climate change.” Cattle have become a hot topic among environmental scientists due to their enormous production levels of a renewable energy source.

Cow power farms work by conveying the manure to covered tanks or lagoons. Gas collecting devices receive the methane as it rises out of the waste load and, with a small amount of processing, pipe the natural gas to an energy utility company’s distribution system. On the other side of the country, Central Vermont Public Service, an electric utility company, uses manure methane to fuel an energy generator and converts the output to electricity for its customers. A Vermont environmental planner Jason Bregman has predicted, “The next generation of renewable energy systems will seek out organic matter in municipal, commercial and agricultural waste streams as a relatively easy source of fuel to obtain and process energy.” Other states and many other countries have begun their own methane waste-to-energy programs.

Reducing the methane a cow produces requires adjustments to the cow’s diet. Grasses that cattle graze contain a stringy fiber called lignin that can only be digested with cud chewing and the action of the rumen’s anaerobes. Laboratories have begun to develop new grasses that contain less lignin so that grass-fed beef and dairy cows emit less methane. The Carnegie Mellon University engineer Christopher Weber explained to Discovery magazine in 2008, “Genetically modified grass could be an appealing solution. It could be more acceptable to the carnivores among us than meat grown in test tubes or giving up meat altogether.” The promise of adjusting cattle’s diets offers some promise, but it is still a long way from helping solve climate change. A more daunting obstacle comes from the fact that cattle are not the world’s only methane producers. The following ruminant animals all produce methane: alpacas, antelopes, bison, camels, deer, giraffes, goats, llamas, oxen, pronghorns, sheep, water buffalos, wildebeests, and yaks.

Methane use and methane reduction are two rapidly emerging technologies. If environmental engineers can design successful means of capturing methane for energy use, they will certainly help in advancing sustainable energy sources. Overall, methane will continue to be a problem in global warming.

Gray Water Reuse

Gray water is water that has been used for showering, faucet uses, and clothes washing, and it usually disappears down drains as a wasted resource. Sustainable wastewater treatment involves the recapture of gray water for additional uses, a process better known as water reclamation. These recovery systems do not collect kitchen sink water or toilet water because these can be health hazards due to the presence of disease-causing microbes.

Sustainable houses collect gray water in pipes that run separate from toilets and the kitchen sink. After collection, building designers have options regarding how and where the gray water will be best used. The three main options for gray water use are: (1) as irrigation water; (2) for flushing toilets; or (3) in the home’s fire suppression system.

Two new technologies may soon join the three main uses for gray water. The first involves the routing of gray water into wetlands constructed near the building to naturally degrade liquid wastes. These constructed wetlands work similarly to natural wetlands in which wastes move very slowly through the site so that plants and microorganisms have time to degrade the organic matter. Lori Ryker explained in her 2005 book Off the Grid, “The goal of a man-made wetland is to replicate a natural wetland’s ability to clean and filter water. A constructed wetland system’s selected plants filter gray water in a specific order, and then return the water to the earth, eliminating the need for a fully developed septic system.” The second technology uses very efficient filtration systems to make the water suitable for drinking, known as potable water. The following filtration technologies may soon produce drinking water for direct reuse as potable water: ultrafiltration in which filters contain extremely small pores to capture all contaminants; nanotechnology in which nanoscale materials act to clean or even sterilize water; and reverse osmosis in which water is forced through a fine membrane to clean out all impurities.

A sustainable home manages three different water sources: (1) rainwater, which is usually captured in a cistern such as the 60-gallon (227-l) size shown here; (2) gray water, which is wastewater from showers, sinks, and washers that is not expected to contain diseasecausing microbes; and (3) blackwater, which is wastewater from toilets, sinks, or any other source expected to be contaminated with disease-causing microbes. (Natural Rainwater.com)

Most houses that recover gray water today send the water to a holding tank that degrades waste in a manner similar to a septic tank. The cleaned water moves out of the tank by passive energy; it is pushed along by the force of new gray water entering the system. The cleaned water flows through a short series of baffles that prevent most of the dirty gray water from mixing with the cleaner water, and then the cleaned water goes through the outflow pipe. After completing this cleanup process, the two main current uses for gray water are garden irrigation or flushing toilets. Gray water reclamation does not need to be confined to houses; these closed-loop systems can work in large office buildings, schools, and manufacturing plants.

Anaerobic Digesters

An anaerobic digester is any equipment or site that holds waste materials in an oxygen-free environment so that anaerobic bacteria can degrade the wastes. On a wastewater treatment plant’s property, the digester is a large tank that holds several thousand gallons of liquid and semiliquid material. Wastewater digestion also takes place in a similar way in lagoons or ponds even though these places are exposed to the air. Though the upper layers of the water contain some dissolved oxygen, the deeper layers become less aerobic and more anaerobic. If the contents of an anaerobic digester or pond receive little mixing, oxygen does not penetrate the depths and so anaerobic bacteria work at their best.

Anaerobic decomposition occurs naturally in swamps, bogs, stagnant ponds, deep bodies of water, and waterlogged soils. The bacteria in these places degrade organic matter to the simplest of compounds, which allows the nutrients to be recycled. For example, amino acids degrade to carbon dioxide (CO2), methane (CH4), hydrogen (H2), and small amounts of nitrogen and sulfur compounds.

Digestion of organic matter—in nature as well as in a digester—takes place in three stages. First, aerobic bacteria degrade complex compounds such as starches, proteins, and fibers into smaller carbohydrates or peptides. A second group of bacteria use these compounds as food and produce organic acids as end products of their enzyme reactions. The organic acids all have in common a carboxylic group as part of their structure (COOH). This section of the molecule contains a carbon that is linked both to an oxygen molecule and to an oxygen-hydrogen complex, called a hydroxyl group. Examples of the organic acids produced in this step are acetic acid (two total carbons), propionic acid (three carbons), and butyric acid (four carbons). As a third and final step, anaerobic bacteria use the acids for energy and produce methane, carbon dioxide, and a small amount of other gases (hydrogen, carbon monoxide, hydrogen sulfide, and nitrogen).

Anaerobic digesters at wastewater treatment plants make fuel in the form of methane gas, which can be burned to release its energy. Many sustainable wastewater treatment plants use the methane to provide heat for the digester so that the entire process can continue. This is an example of a sustainable loop.

The methane and the other biogases produced by anaerobic digestion serve as an energy source that can be used to run the treatment plant or do other work. Burning one cubic foot of biogas yields 10 Btu of heat energy. The amount of methane in the biogas mixture affects the energy production because methane is the main energy source. Each percentage of methane results in 10 Btu, so that a biogas containing 65 percent methane produces 650 Btu per cubic foot. Very active anaerobic digesters can produce enough methane to run a treatment plant’s heating, refrigeration, and electricity. Anaerobic digesters therefore play a role as the main powerhouse when designing a sustainable wastewater treatment plant.

Methane cannot solve every environmental problem. For one thing, though methane can be used for making energy, it is also a predominant greenhouse gas that causes global warming. Sustainable wastewater treatment plants help reduce this problem by capturing all the methane emitted by a digester and using it, but methane come from additional sources in the world. Human activities that lead to methane production are waste treatment, biomass burning facilities, energy plants, and landfills. Methane also comes from natural sources: anaerobic soil and water bacteria, some vegetation, fossil fuel deposits such as coal mines and natural gas fields, and certain animals. Scientists have begun to realize in the past decade or so that the animal sources of methane contribute a significant amount of greenhouse gas to the atmosphere.

Kufunda Learning Village, Zimbabwe

Kufunda Learning Village in Zimbabwe, located near the capital of Harare, was created in 2005 by Marianne Knuth for the purpose of creating strong, healthy communities that are responsible for their own future. In addition to cultural growth, Kufunda has embarked on an exploration of technologies to meet its most immediate needs. Kufunda residents focus on building self-sufficiency in two main areas: agriculture and community infrastructure. Knuth explained, “We are a small group of people who have decided to create a learning village aimed at the creation of locally rooted solutions to community self-reliance challenges. A starting assumption for my work here is that people already know how to work in creative and self-sufficient ways, and that the challenge is to help them access that knowledge—and the self-confidence to act on it—generating concrete and often surprising results in the process.” In time, Kufunda’s residents hope they can transfer their knowledge to neighboring villages that wish to create similar self-sufficiency.

In the face of periodic political unrest, villages like Kufunda have a greater need for self- reliance, perhaps, than any other communities. Residents have begun to investigate the developmentment of ecological projects such as renewable energy, organic farming, ecological building, and composting toilets. The Kufunda Learning Village Web site has reported, “Ecological sanitation is a system that makes use of human excreta and turns it into something useful, which can be used to grow plants or trees. By now all the toilets at the village are of this type. Our simplest compost toilet can now be built for roughly 10 U.S. dollars—an important factor when working with financially poor rural communities.” Not only are Kufunda’s plans cost-effective, but they make every use of natural clean-running systems.

The Kufunda Learning Village has already begun to run its main electronic systems on solar power—the satellite Internet was the village’s first system to run on solar energy. Kufunda’s residents have an advantage over richer, more industrialized communities: They own no preexisting energy or waste management systems to tear down. The Kufunda Learning Village continues to find the best solutions to its specific environmental issues and, in the process, provides a good example of building efficient and simple technologies that foster sustainability.

Wastewater in Developing Countries

Numerous developing parts of the world contend with a high incidence of infectious disease because of poor drinking water quality and poorly functioning wastewater systems. Leaks and contamination of either system come from faulty or missing infrastructure, meaning distribution pipes, collection pipes, treatment facilities, and disinfection methods. Because of serious health threats to humans, many developing countries that already struggle with poor infrastructure make wastewater treatment their priority. The World Health Organization (WHO) has warned that the problem will get worse in developing countries. Because these places have clean water shortages, wastewaters substitute for treated water for irrigation, fishing, and cleaning clothes.

Sustainable wastewater treatment refers to the production of energy from the wastewater treatment process. This method of energy production offers an opportunity for developing countries for two reasons: the efficiency in converting biomass’s chemical energy to other forms of energy, and low cost compared with other energy technologies. Sustainable wastewater treatment therefore relieves two problems that plague many developing parts of the world: energy and waste management.

Nonindustrialized countries have a great need for inexpensive, easyto- build waste treatment technologies. Some of these countries have adopted inventive and sustainable solutions to waste treatment. The Internet reporter Andrea Millar provided an example in a 2008 article: “A Kenyan jail has confronted the issue of its waste production by creating a sustainable wastewater treatment facility staffed by inmates and designed by both local and international organizations. Rather than employ hightech engineering, the bulk of the [treatment is] handled by natural processes in the facility’s man-made wetlands. Acting as a vast filtration system, the sustainable processes of anaerobic microbes convert human waste into materials for biogas and water for use on the jail’s vegetable fields.” Millar’s example illustrates a situation in which wastewater handling is done in a manner that requires no energy input at all other than a small amount of manual labor.

The next step in sustainable wastewater use involves methods for producing energy. Treatment plant anaerobic digesters offer the most efficient way to make energy-containing methane gas, but some villages may not have the funds to build a new plant from the ground up. A waste treatment pond offers an inexpensive option because it contains conditions similar to those found inside treatment plant anaerobic digesters. Treatment ponds contain anaerobic activity in the deepest parts of the pond where aerobic bacteria have depleted the oxygen. Anaerobic bacteria live naturally in these types of places so setting up a wastewater treatment pond carries little expense. Methane gas drifts up from the bottom of the pond and can be captured and piped to an energy-generating plant so that the pond produces energy rather than consumes it.

Some ponds tend to grow heavy mats of algae on the water surface. Rather than spend efforts to get rid of the algae, workers remove the algae layer and add it to a small anaerobic digester to produce heat. In fact, treatment ponds provide the same advantages of mechanical anaerobic digesters: They help in waste management and treatment and recycle nutrients. One disadvantage of ponds compared with closed anaerobic digesters comes from odors emitted by the bacteria in their normal digestion of organic matter. The odors do not cause a health problem, but smell unpleasant.

R. Otterpohl wrote an online article in 2007 for the Swiss Federal Institute of Aquatic Science and Technology describing new processes for wastewater treatment that seem suited for developing countries: “The conventional wastewater management concept, consisting of a waterborne wastewater collection system leading to a central treatment plant, has been successfully applied over many decades in densely populated areas of industrialized countries . . . However, the appropriateness of this model in the context of developing world cities must be questioned, given the urgent need for affordable, sustainable infrastructure. During the last decade, various researchers and institutions, including the World Bank, have started to consider the decentralized wastewater management approach as an alternative to conventional centralized systems, but these approaches have struggled to gain acceptance.” Part of the resistance comes from the worry that treatment plants intended for the use of only one or two towns might not be as efficient to run as big centralized wastewater treatment plants. But small, decentralized treatment plants also offer advantages to communities, as follows:

1. smaller treatment systems tailored to a community’s specific needs
2. experimentation with different wastewater treatment methods
3. reduces accidents that may occur in long-distance wastewater shipment
4. increases opportunities for treated water reuse
5. makes incremental changes and improvements manageable

 Today, the Engineers Without Borders-International (EWBI) organization helps communities in developing regions adopt new technologies to improve their health, income, and lives. The EWBI stresses sustainable methods in energy use, water management, and native natural resource conservation. EWBI engineers and other volunteers help disadvantaged communities build needed structures and teach residents basic engineering skills for future projects. The founder of the Engineers Without Borders-United States, Bernard Amadei, revealed his view of the organization’s purpose in a 2007 interview with the correspondent Spencer Michels. Amadei described San Pablo, Belize, as a village “where I noticed a lot of little girls, young girls, who were carrying water—that was their job—from the river to the village, back and forth, back and forth. And as a result, they could not go to school. It broke my heart. And I decided I was going to do something about it.” EWBI develops projects with a community, not for it, so that the community solves its own environmental engineering needs. EWBI helps train residents how to build a structure, how to fix it, and how to keep it running.

Developing countries therefore have options for the type of wastewater treatment they choose. Because of the health needs for safe wastewater management and the need to produce inexpensive energy, sustainable wastewater systems are ideal for developing parts of the world.

The Energy-Water Connection

Environmental engineers apply the first and second laws of thermodynamics in every project they plan and develop. The first law of thermodynamics states that energy can neither be created nor destroyed. The form of energy, however, can change. For example, the motion energy inside a turbine changes to electricity. The second law of thermodynamics states that energy flows from a region of high concentration to a region of lower concentration, much as water flows downhill. By the second law of thermodynamics, water at the top of a waterfall contains a high concentration of energy. As it pours over the waterfall and fills a basin, the energy concentration changes. The water that settles into the basin at the bottom of the waterfall holds a lower concentration of energy. This principle has been used for centuries to power daily operations.

Flowing water illustrates another component of energy—potential energy versus kinetic energy. Water at the top of the waterfall before flowing over the edge contains potential energy, that is, a form of stored energy. As the water pours downward it loses potential energy and gains kinetic energy, the energy of motion. All of the different types of energy

Operations that generate energy from flowing water—hydroelectric dams, wastewater treatment plants, mills— rely on capturing water’s kinetic energy. Water at the top of the waterfall in this diagram holds high potential energy, but after it reaches the bottom of the waterfall it contains low potential energy. Power plants take advantage of this transition.

in the solar system can be classified as either potential or kinetic, as the following table shows.

Energy can change from one type to another, as mentioned, illustrated by the following example:

1. A racehorse converts the chemical energy in hay to motion energy.
2. A person converts electrical energy to thermal energy by turning on an oven.
3. Plants convert radiant energy from the Sun into chemical energy through photosynthesis.

Water’s use as an energy source throughout history has usually been as motion energy. Wastewater treatment plants can take advantage of the natural flow of water to power operations, but wastewater offers an additional energy source in the form of biomass. Biomass is organic matter in wastewater that comes from plant and animal wastes. In the wastewater treatment industry, biomass represents a source of chemical energy that can be converted to other forms such as thermal energy.

Sustainable Wastewater Treatment

Hydrology, the science of water systems, has always been a central part of environmental engineering. Ancient societies used flowing water as a means of travel, a conveyance for moving timber and other goods downstream, and a waste disposal system. During the growth of civilization, people learned that bodies of water held a significant amount of force. Villages constructed mills next to fast flowing rivers to let the force of the water supply power for the milling operations. The next generation built enormous dams to control the force of water that powered turbines and produced electricity. Water systems will become part of new energy-generating systems in sustainable communities in the near future, mainly because water avoids the use of nonrenewable and pollution-causing fossil fuels.

Wastewater treatment follows a standard process that turns raw sewage into disinfected water safe for return to the environment. Almost all modern wastewater treatment plants conduct the following steps to treat wastewater: (1) wastewater passes through screens that remove large solids; (2) wastewater enters a grit chamber where heavy wastes settle out of the water by gravity; (3) water enters a larger settling tank where light, small particles slowly settle out of the water; (4) the water enters an aeration tank containing aerobic (oxygen-requiring) bacteria that digest organic substances, aided by a constant bubbling of air through the contents; (5) the water enters another settling step and then passes through a filtration tank, which removes very fine particles; (6) disinfectant kills the bacteria in the water; and (7) the treated water discharges into the environment.


Pipes carry much of the heavy organic sludge that collects in the settling tanks to another tank called an anaerobic digester. This digester contains anaerobic (requiring the absence of oxygen) bacteria that slowly degrade the heavy sludge and produce methane and small amounts of other gases. The wastewater treatment industry calls the methane biogas, and both biogas and solid biomass serve as energy sources produced by wastewater treatment.

Landscape Design Skills

The landscape design profession combines art and science for the purpose of planning and shaping the land that surrounds a structure. Ecological landscape design focuses on meeting a customer’s needs while also planting trees and plants, gardens and ponds, and other features that create a relationship between the building and the environment. Landscape designers must understand many of the same principles as environmental engineers, that is, hydrology, geography, topography, and climatology. The landscape designer, however, emphasizes the artistic use of plants, water, and land. The following table summarizes the basic skills that landscape designers call upon when they develop a new but natural look for a parcel of land.

Environmental landscaping begins with a plan agreed upon between a house’s architect and the property’s landscaper. A landscape designer also gives input to this process in order to create a visual meaning to an entire property. For instance, a country cottage would look out of place nestled among large rock formations and towering pines, and the property would be further confused by a modernistic landscape design including sculpted shrubbery and enormous fountains. Landscaping in harmony with nature eliminates most of these pitfalls: Nature always produces the best balance between art and design.

The landscape design process entails the following six steps:

1. Develop a design for a given parcel of land.
2. Conduct a site analysis to assess existing tree and plant life and physical features.
3. Assess the house design, landscaping objectives, and the residents’ desires.
4. Locate areas of the property that will be designed.
5. Create design plans for those individual areas.
6. Select the plants to be used and plant them in the designated areas.

 In order to carry out the tasks listed here, landscape designers depend on strong skills in horticulture. In this way they help eco-landscapers select plant life that blends with the following factors: local climate and any microclimates; soil conditions; wind and storm incidence; and potential freezing or drought. Landscape designers today also design biodiversity gardens and edible gardens.

America’s Scenic Byways

Since 1991 the U.S. Department of Transportation (DOT) National Scenic Byways Program has designated specific roads that lead to archaeological, historical, cultural, natural, recreational, or scenic locations. The DOT has so far designated 125 such roads in 44 states. All of the scenic byways encourage travelers to gain greater appreciation of the land and its local trees, plants, and wildlife. Because scenic byways often call attention to nature, they seem to be a perfect place to adopt ecolandscaping. But heavily traveled roads have also caused harm to biodiversity by breaking up habitats, blocking migration routes, and killing wildlife in road accidents. Current and future scenic byways hold an important opportunity to establish ecologically friendly methods to construct and maintain popular roads.

Scenic byways range in rustic quality from the Beartooth Highway that meanders through Montana’s mountains and forests to Delaware’s Brandywine Valley Scenic Byway that travels past large estates and magnificent botanical gardens. Regardless of the terrain that a scenic byway traverses, the program ensures that all portions of the highway minimize the presence of billboards, telecommunications towers, fast food restaurants, or other clutter. One goal of the scenic byways program involves saving open space, and keeping human activities away from the roads helps preserve open space. In many instances, scenic byways probably provide some people with a look at nature that they would otherwise miss entirely in their urban lifestyle.

Walkways and Driveways

Rainfall that seeps into the earth receives cleaning as it percolates past soil particles that remove chemicals and microbes. The water then trickles downward into natural aquifers that serve as underground reservoirs for clean drinking water. When communities pave over the ground for roads, driveways, and parking lots, rainwater can do nothing but rush downhill into streams and then to wastewater treatment plants. This event has two drawbacks: Rainwater does not become available for plants and aquifers, and the extra volume of water requires extra energy consumption by wastewater treatment plants. Stress put on treatment plants can be significant in heavy storms, and the incidence of drinking water contamination increases when storms overtax local wastewater treatment facilities. For these environmental and health reasons, permeable pavements offer a useful way to manage and conserve water.

Porous surfaces act as one of the best ways to reuse rainwater and irrigation water. They also reduce runoff to streams. (A) An ecological garden uses stones to create a pathway that allows water to enter the soil. The gardener has planted thyme between these stones. (Kurt Lawton) (B) A pebble driveway helps in water recycling much more than a paved driveway. (Bushnell House)

A permeable pavement is any material that provides pedestrians or vehicles with a strong surface but also allows water to drain through rather than run off the surface. Landscapers select from five main types of permeable pavements, described in the following table.

Permeable pavements must be selected with the soil conditions in mind. For example, clay soils do not drain well and have a tendency to turn to mud in heavy rains. Areas with a very high water table, meaning the area’s natural groundwater storage is close to the surface, present the opposite problem: Permeable materials allow too much water to enter already soaked conditions. Even the best-designed permeable pavements can clog and may need extra maintenance to keep them open.