Category: Engineering

Wall Collection Devices (Air Pollution)

Wall Collection Devices (Air Pollution)

Wall Collection Devices (Air Pollution)

01/14/26

“How can we remove particulate matter by sticking it on a wall?”

Particulate matter emissions are harmful to nearby communities. Consequently, people use technology to remove as much particulate matter as possible before emitting. One set of technologies sticks particulate matter on walls to form conglomerations, which can be removed later. TheseWall Collection Devices can work by forcing particles to drop from gravity, hit a wall due to sudden direction changes, or move due to electrostatic attraction. These wall collection devices help the health of countless towns around the world.

Image credit: https://www.graco.com/

Compost Filter Socks

Compost Filter Socks

Compost Filter Socks

01/13/26

“How can we use a mesh tube filled with compost to clean water runoff?”

                Stormwater runoff with sediment can harm nearby water bodies and create erosion. So what if we were to take a mesh tube, fill it with compost, and encircle it around an area of interest? Every time water passes through the tube, compost will slow the runoff down and naturally filter the water. These Compost Filter Socks are typically placed along slope contours, near storm drain inlets, and downslope of physically disturbed areas. Compost filter socks are a great tool for stormwater runoff control, erosion prevention, and environmental safety.

Image credit: https://images.squarespace-cdn.com/

Formaldehyde

Formaldehyde

Formaldehyde

01/12/2026

“What’s so special about formaldehyde?”

Chemicals come in all sorts of forms. CH2O, also known as Formaldehyde, is a very special chemical. Formaldehyde-based resins are an incredibly effective and affordable option to use as glue in engineered wood for construction. It has strong performance in humid and high temperature variability environments and can insulate well. However, it’s also a volatile organic compound that hurts the respiratory system and is also a carcinogen at sufficient exposure. Consequently, many engineering companies are phasing formaldehyde out of their inventory.

Air Changes Per Hour

Air Changes Per Hour

Air Changes Per Hour

01/10/2025

“How can we quantify how many times air is replaced in a room per hour?”

Air can get stuffy and polluted if it stays in a building for too long. People replace air over time to ensure it’s fresh on the inside. The number of times air is changed per hour is quantified by the Air Changes Per Hour. The air change per hour is quantified by taking the volume of air that is transferred from the outside per hour in a room and dividing it by the room volume. The U.S. CDC recommends an air change of at least 5 air changes per hour to reduce the number of viruses in a building.

Sloped Green Roofs

Sloped Green Roofs

Sloped Green Roofs

01/09/26

“What are the advantages and disadvantages of sloping a green roof?”

Green roofs integrate stormwater management, biodiversity, building insulation, and aesthetic design all into one package. We can also pitch these green roofs at a slight angle to make Sloped Green Roofs. Sloped green roofs reduce ponding and may improve aesthetic appearance, but are also structurally and hydrologically more complicated. Stormwater runs off more from sloped green roofs, meaning roof plants may have to rely on other sources of water. 

Soil Slope Toe

Soil Slope Toe

Soil Slope Toe

01/06/26

“What defines the base of a soil slope?”

Construction sites often have sloping soil mounds. The bottom section with a gentle slope that meets the ground is known as the Soil Slope Toe. The soil slope toe is important because it often experiences the highest stress and is where erosion concentrates.

Minimum Vertical Separation From Water Table

Minimum Vertical Separation From Water Table

Minimum Vertical Separation From Water Table

01/05/26

“Why do some engineering systems require a minimum vertical separation from the water table?”

Engineering systems may store water beneath the surface, such as septic systems for wastewater or infiltration systems for stormwater. However, these systems can cause catastrophic damage if they’re built too close to the water table. Septic systems can leach wastewater and contaminate groundwater supplies, while water infiltration can raise the water table and lead to flooding. Consequentially, government regulations may require a Minimum Vertical Separation From Water Table to ensure public safety. For example, the NYC Department of Environmental Protection mandates that stormwater infiltration practices in Brooklyn and Queens are at least 4 feet above the groundwater table.

Image credit: https://michigansaves.org/

Builders Pavement Plans

Builders Pavement Plans

Builders Pavement Plans

01/04/25

“What regulations do you have to follow if you install or alter curbs, sidewalks, or roadways in NYC?”

Different municipalities have different regulations for different construction activities. In NYC, people who install or alter curbs, sidewalks, or roadways are required to submit a Builders Pavement Plan, or BPP. The builders pavement plan documents what actions the construction operator is taking to install/alter their right-of-way infrastructure and how they will follow regulations. The NYC Department of Buildings reviews BPP applications and analyzes how they comply with city construction codes and NYC Department of Transportation rules, regulations, and standards. BPPs help ensure NYC’s urban planning stays strong and that city residents are offered a safe environment.

Common Plan of Development

Common Plan of Development

Common Plan of Development

01/03/26

“How can we build a large project in multiple distinct phases?”

Large construction projects often need to comply with stringent size-based regulations. Developers might subvert this by breaking up a large project into multiple sub-projects. To prevent this, U.S. governmental regulatory authorities will define projects with the same owner/developer completed in the same larger development plan as part of a Common Plan of Development. Permits will use the acreage of the total common plan of development to ensure construction operators meet planning requirements, such as stormwater pollution prevention plans.