Incorporating green infrastructure into transit street design can improve water quality, detain stormwater flows, reduce the volume of stormwater runoff, and relieve burden on municipal water treatment systems.

 

Incorporating green infrastructure into transit street design can improve water quality, detain stormwater flows, reduce the volume of stormwater runoff, and relieve burden on municipal water treatment systems.

Green infrastructure can complement transit by calming traffic, enhancing comfort while waiting for transit, and creating opportunities for safer pedestrian crossing at bus bulbs and curb extensions with green infrastructure.

APPLICATION

Integrate green infrastructure into sidewalks, medians, curbs, and other features, including bioswales, flow-through planters, or pervious strips.

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At stations and terminals, an enhanced landscape can improve aesthetic appearance, user comfort, and ecological performance.

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BENEFITS

A tree canopy and green features can improve transit experience for waiting riders, increasing comfort and reducing perceived wait time.

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Green infrastructure improves the natural ecosystem and reduces harmful pollutants. Where vehicles leave oil and other pollutants on the road surface, a bioswale facility can prevent large amounts of pollution from entering the watershed.

CONSIDERATIONS

Select appropriate plantings; in dry climates, drought-resistant landscaping (xeriscaping) reduces water and maintenance requirements.

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Choose green infrastructure based on pedestrian volume and the intensity of use on a sidewalk.

RECOMMENDED

As required, install a perforated pipe at the base of the facility to collect the treated runoff.

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Bioswales have a slight longitudinal slope that moves water along the surface to allow sediments and pollutants to settle out. In-place infiltration then allows localized groundwater to recharge. Ideal side slopes are 4:1, with a maximum slope of 3:1. Use a maximum 2% gentle side slope to direct water flow into the facility.Use appropriate media composition for soil construction. The engineered soil mixture should consist of 5% maximum clay content.

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The planter should drain within 24 hours; this is especially critical near transit stops where pooling can degrade transit access.

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Ensure that infiltration rates meet their minimum and maximum criteria. The engineered soil mixture should be designed to pass 5–10 inches of rain water per hour.

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Where a near-side boarding bulb is combined with a turn restriction, design the curb to self-enforce the turn restriction and monitor closely to ensure that transit vehicles are not suffering from delays.

 

Drinking water sources are subject to contamination and require appropriate treatment to remove disease-causing agents

Community Water Treatment

Drinking water supplies in the United States are among the safest in the world. However, even in the U.S., drinking water sources can become contaminated, causing sickness and disease from waterborne germs, such as Cryptosporidium, E. coli, Hepatitis A, Giardia intestinalis, and other pathogens.

Drinking water sources are subject to contamination and require appropriate treatment to remove disease-causing agents. Public drinking water systems use various methods of water treatment to provide safe drinking water for their communities. Today, the most common steps in water treatment used by community water systems (mainly surface water treatment) include:

 

Coagulation and Flocculation

Coagulation and flocculation are often the first steps in water treatment. Chemicals with a positive charge are added to the water. The positive charge of these chemicals neutralizes the negative charge of dirt and other dissolved particles in the water. When this occurs, the particles bind with the chemicals and form larger particles, called floc.

Sedimentation

During sedimentation, floc settles to the bottom of the water supply, due to its weight. This settling process is called sedimentation.

Filtration

Once the floc has settled to the bottom of the water supply, the clear water on top will pass through filters of varying compositions (sand, gravel, and charcoal) and pore sizes, in order to remove dissolved particles, such as dust, parasites, bacteria, viruses, and chemicals.

Disinfection

After the water has been filtered, a disinfectant (for example, chlorine, chloramine) may be added in order to kill any remaining parasites, bacteria, and viruses, and to protect the water from germs when it is piped to homes and businesses.

Water may be treated differently in different communities depending on the quality of the water that enters the treatment plant. Typically, surface water requires more treatment and filtration than ground water because lakes, rivers, and streams contain more sediment and pollutants and are more likely to be contaminated than ground water.

Some water supplies may also contain disinfections by-products, inorganic chemicals, organic chemicals, and radionuclides. Specialized methods for controlling formation or removing them can also be part of water treatment. To learn more about the different treatments for drinking water, see the National Drinking Water Clearinghouse’s Fact Sheet Series on Drinking Water TreatmentsExternal.

To learn more about the steps that are taken to make our water safe to drink, visit the United States Environmental Protection Agency’s (EPA) Public Drinking Water Systems webpageExternal. To learn more about the 90+ contaminants EPA regulates and why, visit EPA’s Drinking Water ContaminantsExternal page.

Water Fluoridation

Community water fluoridation prevents tooth decay safely and effectively. Water fluoridation has been named one of 10 great public health achievements of the 20th century ¹. For more information on the fluoridation process and to find details on your water system’s fluoridation, visit CDC’s Community Water Fluoridation page.

Consumer Confidence Reports

Every community water supplier must provide an annual report, sometimes called a Consumer Confidence Report, or “CCR,” to its customers. The report provides information on your local drinking water quality, including the water’s source, contaminants found in the water, and how consumers can get involved in protecting drinking water.

Household Water Treatment

Even though EPA regulates and sets standards for public drinking water, many Americans use a home water treatment unit to:

• Remove specific contaminants
• Take extra precautions because a household member has a compromised immune system
• Improve the taste of drinking water

Household water treatment systems are composed of two categories: point-of-use and point-of-entryExternal (NSF). Point-of-entry systems are typically installed after the water meter and treat most of the water entering a residence. Point-of-use systems are systems that treat water in batches and deliver water to a tap, such as a kitchen or bathroom sink or an auxiliary faucet mounted next to a tap.

The most common types of household water treatment systems consist of:

Filtration Systems
A water filter is a device which removes impurities from water by means of a physical barrier, chemical, and/or biological process.

Water Softeners
A water softener is a device that reduces the hardness of the water. A water softener typically uses sodium or potassium ions to replace calcium and magnesium ions, the ions that create “hardness.”

Distillation Systems
Distillation is a process in which impure water is boiled and the steam is collected and condensed in a separate container, leaving many of the solid contaminants behind.

Disinfection
Disinfection is a physical or chemical process in which pathogenic microorganisms are deactivated or killed. Examples of chemical disinfectants are chlorine, chlorine dioxide, and ozone. Examples of physical disinfectants include ultraviolet light, electronic radiation, and heat.

 

Exposure to ground-level ozone can cause respiratory issues, aggravate asthma and other lung diseases

 

EPA Strengthens Key Power Plant Rule to Reduce Smog this Summer and Improve Air Quality for Millions of Americans

WASHINGTON — The U.S. Environmental Protection Agency (EPA) is finalizing revisions to the Cross-State Air Pollution Rule (CSAPR) Update to help areas affected by pollution emitted by power plants in other states meet the 2008 national ambient air quality standards (NAAQS) for ground-level ozone, commonly referred to as smog. Starting this summer, power plants in 12 states will be required to cut smog-forming emissions of nitrogen oxides (NOx) that contribute to unhealthy air quality in communities downwind by installing, improving or upgrading pollution controls. Exposure to ground-level ozone can cause respiratory issues, aggravate asthma and other lung diseases and lead to missed days of work or school, emergency room visits and premature deaths. 

“EPA plays a critical role by working with states and the power sector to prevent pollution released in one state from harming the health and air quality of its neighbors,” said EPA Administrator Michael Regan. “The action we are taking today will not only help states meet their clean air obligations, but, more importantly, deliver cleaner, healthier air to millions of Americans starting this summer.”

EPA estimates that the Revised CSAPR Update will reduce NOx emissions from power plants in 12 states in the eastern United States by 17,000 tons beginning in 2021 compared to projections without the rule. Due to this rulemaking and other changes already underway in the power sector, ozone season NOx emissions in these 12 states will be nearly 25,000 tons lower in 2021 than in 2019, a reduction of 19 percent. The reduction in emissions is estimated to prevent about 290,000 asthma events, 560 hospital and emergency room visits, 110,000 days of missed work and school, and up to 230 premature deaths in 2025. The public health and climate benefits are valued annually, on average, at up to $2.8 billion each year over the period 2021 to 2040.

Required at power plants in 12 upwind states, the additional emissions reductions are based on both improving the performance or utilization of pollution controls already installed beginning in the 2021 ozone season and installation or upgrade of state-of-the-art NOx combustion controls beginning in the 2022 ozone season. The reductions in NOx emissions will lead to significant improvements in air quality beginning in the 2021 ozone season, which starts in May.

During warm weather months, NOx emissions from power plants can react in the atmosphere to create ground-level ozone, or smog. These pollutants can travel great distances, often crossing state lines and making it difficult for other states to meet and maintain the air quality standards for ozone that EPA establishes to protect public health.

Projected 2021 emissions from power plants in Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Virginia, and West Virginia were found to contribute to pollution levels that would harm the ability of downwind states to meet or maintain the 2008 ozone NAAQS. 

The rule responds to the September 2019 ruling by the U.S. Court of Appeals for the D.C. Circuit (Wisconsin v. EPA) by addressing the “significant contribution” of pollution from particular upwind states to downwind states under the authority provided in Clean Air Act’s “good neighbor” section 110(a)(2)(D)(i)(I), in order to help downwind states meet and maintain compliance with the 2008 ozone standard.

Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) - Methods and guidance for sampling and analyzing water and other environmental media

 

Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS)  - Methods and guidance for sampling and analyzing water and other environmental media

Background

Per-and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals that have been in use since the 1940s. PFAS are found in a wide array of consumer and industrial products. PFAS manufacturing and processing facilities, facilities using PFAS in production of other goods, airports, and military installations are some of the contributors of PFAS releases into the air, soil, and water. Due to their widespread use and persistence in the environment, most people in the United States have been exposed to PFAS. There is evidence that continued exposure above specific levels to certain PFAS may lead to adverse healtheffects.The U.S. Environmental Protection Agency (EPA) will continue to partner with other federal agencies, states, tribes, and local communities to protect human health and, where necessary and appropriate, to limit human exposure to potentially harmful levels of PFAS in the environment.

 

EPA’s methods for analyzing PFAS in environmental media are in various stages of development and validation. The Agency is working to develop validated analytical methods for groundwater, surface water, wastewater, and solids, including soils, sediments, biota, and biosolids.

Drinking Water

Analysis of PFAS using Method 537.1

To assess for potential human exposure to PFAS in drinking water, EPA’s validated Method 537.1 will ensure that both government and private laboratories can effectively measure 18 PFAS in drinking water, which is a critical step for estimating exposure and potential health risks to PFAS. EPA Method 537 was first published in 2009 to initially determine 14 different PFAS. In 2018, the method was updated to include 4 more PFAS,including the GenX chemical hexafluoropropylene oxide dimer acid(HFPO-DA).

Analysis of Short-Chain PFAS using Method 533EPA developed and validated EPA Method 533 to target “short chain” PFAS (none greater than C12), including perfluorinated acids, sulfonates, fluorotelemers,and poly/perfluorinated ether carboxylic acids. Many of these could not be analyzed using 537.1 due to physicochemical properties. In December 2019, EPA published Method533, which includes a total of 25 PFAS (14 of the 18 PFAS in 537.1 plus an additional 11 “short chain” PFAS) and specifies isotope dilution quantitation.

Health Advisories

In May 2016, EPA issued drinking water health advisories for two types of PFAS: perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). EPA's health advisories are non-regulatory and non-enforceable ,and are intended toprovide technical information to state agencies and other public health officials on health effects, analytical methodologies, and treatment technologies associated with drinking water contamination.

Non-Potable Water

Analysis of PFASusing SW-846 Method 8327

EPA developed a direct injection liquid chromatography tandem mass spectrometry method, EPA SW-846 Method 8327,that utilizes external calibration for analysis of 24 PFAS in non-potable water (not of drinking quality). After a multi-lab validation in surface water, groundwater, and wastewater effluent, EPA posted the validatedSW-846 Method 8327 in June 2019 for public comment. In 2019, EPA published validated SW-846 Method 8327 for non-potable water and Method 533 for analysis of short-chain PFAS in drinking water.

U.S. Environmental Protection Agency 2EPA SW-846 Method 8327 is available for public use while EPA is adjudicating public comments. Consistent with most SW-846 methods, EPA provides the method as guidance; the use of this method is not specified in any federal testing requirements. Method 8327 is designed for high-throughput applications and supports interim recommendations for groundwater contaminated with PFOA and PFOS; however, for some analytes and matrices, it may not be sensitive enough for very low-level (i.e., single ng/L) project requirements.

Non-Potable Water and other Environmental Media

Validation of SPE-ID Method for PFAS Analysis

EPA is collaborating with the Department of Defense’s Naval Seas Systems Command Laboratory Quality and Accreditation Office and SGS-AXYS to validate a solid-phase extraction/isotope dilution (SPE-ID) method. The method will include solid matrices (e.g., soil, sediment, fish tissue, biosolids) in addition to non-drinking water aqueous matrices.

In addition to the 24 analytes included in draft SW-846 Method 8327, EPA plans to include additional analytes for the SPE-ID Method to include analytes recently added to EPA Method 537.Single-laboratory validation of the SPE-ID protocol is targeted for winter 2020 and multi-laboratory validation will likely follow in 2021.

Evaluating Methods for Total PFAS Assessments

EPA will also begin evaluating methods for total organic fluoride (TOF) analyses in 2020. An effective TOF method will facilitate broad assessments of total PFAS in environmental samples.

Developing Sampling and Storage Methods

EPA ran time-based studies on degradation or loss of target analytes during sample storage (45 days) and assessed the effects of different sample vessel materials (e.g., plastic, glass) on analyte recovery. Based on these sampling and storage studies, EPA methods under development will recommend using PFAS-free, plastic containers (e.g., high-density polyethylene containers); whole sample preparation; and sample holding times of 28 days. EPA will also develop guidelines for field sampling, which are critical for minimizing sample contamination and optimizing data quality for site characterization and remediation. Due to the widespread use of PFAS, many materials normally used in field and laboratory operations contain PFAS. For example, polytetrafluoroethylene products (tubing, sample containers, and sampling tools) are often used in sampling; however, since these products can contain PFAS, they cannot be used in sampling for PFAS. In addition, many consumer goods brought to a sampling site may contain PFAS that can contaminate samples. Field sampling and laboratory hygiene protocols are critical to ensuring that testing results reflect actual PFAS levels in the analyzed media.

The Interstate Technology and Regulatory Council has summarized site characterization, sampling precautions, and analytical method issues and options through their fact sheet series.