Newletters, helpful advice and other pearls of wisdom from Earthworks' staff.
Storm Intensity Producing Sediment Laden Runoff
The intensity of a storm can have a significant impact on soils, causing sediment laden runoff. The greater the intensity, the more sediment that is displaced and carried away in runoff in a shorter amount of time. A longer rain event with the same amount of water will not cause the same displacement as the shorter storm. This is due to several factors. Two of these factors are raindrop to soil impact and inability to infiltrate causing more runoff. With a more intense storm the raindrops...
by Rick Jackson // 2020-08-04Read More
BMPs - The Right Way to Use Them
BMPs such as silt fence, straw wattles, bio logs, erosion control blanket and rip rap are effective ways to control sediment on your construction site, though only if they are installed and maintained properly. For example, when BMP crews install erosion control blankets (ECB) the ECB must match the manufactures specification. This is not just because the ECB works most effective when installed properly, but also to stay in compliance. Often the “easy” way to install a BMP is not the corr...
by Matthew Trygg // 2020-08-04Read More
Texas Stormwater Banking
The Llano river flooding. Credit: Jonathan Cutrer Over the past few years Texas has experienced unpredictable weather ranging from storms that produce severe flooding to extended periods of drought. Stormwater banking is the idea to first capture floodwater in order to help mitigate its impacts to then store it in aquifers and utilize it during dry seasons when little rainfall is occurring. The University of Texas at Austin “quantified the amount of water flowing in major Texas riv...
by Haley Daily // 2020-08-04Read More
Soils: Cohesive versus Cohesionless
Soils get classified as cohesive or cohesionless. A cohesive soil has an attraction between particles of the same type, origin, and nature. Therefore, cohesive soils are a type of soil that stick to each other. Cohesive soils are the silts and clays, or fine-grained soils. A cohesionless coil (non-cohesive) soil are soils that do not adhere to each other and rely on friction. These soils are the sands and gravels, or coarse-grained soils. The soil type is particularly relevant when it com...
by Rick Jackson // 2020-08-04Read More
As many homebuilders have noticed, there has been an increase in NPDES regulatory inspections across the state of Florida. Whether the regulatory inspections are completed by state, county or municipality, it can be very stressful for site supervisors and others involved with NPDES compliance. In most instances, a regulatory inspector will notify the responsible authority of an upcoming inspection. The advanced notice should be used to ensure that all BMPs onsite, as well as the SWPPP, ar...
by Johnathan Clayton // 2020-08-04Read More
Deciding What Temporary Stormwater BMP Works
Choosing the right Best Management Practice (BMP) for a site is very crucial and can be costly if chosen incorrectly. When deciding what stormwater BMP will work, the field conditions that must be considered includes the following: how much water flow will need to be filtered/slowed/redirected, how long the BMP will be in place for, how much pollutant the BMP could potentially receive and are there any items preventing proper installation. Builders must use their best judgement and gather...
by Brooks Morse // 2020-08-04Read More
Maricopa County Air Pollution
The Maricopa County Air Quality Department has the following purpose statement “Working to improve the air of Maricopa County so customers, residents, and visitors can live, work, and play in a healthy environment”. One way to accomplish this is to enforce a strict set of rules that govern specific types pollution and pollution producing activities. One specific pollutant that plagues arid desert areas is particulate matter. So, how much particulate matter, or PM for short is too much and...
by Mark Hubbard // 2020-08-04Read More
Metamorphoses of the Clean Water Act
As urbanization and development activities continue the number of impervious surfaces increases, leading to a rise in volume and rate of stormwater runoff. With higher amounts of runoff, pollutants are more likely to contaminate water if not properly treated. In the early 1970s, two-thirds of the nation’s lakes, rivers, and coastal waters were unsafe for fishing or swimming, and untreated sewage was dumped into open water (Reilly, 2011). Due to this contamination the 1948 Federal Water Po...
by Haley Daily // 2020-08-04Read More
What is a SWPPP?
A Storm Water Pollution Prevention Plan (SWPPP) must be developed prior to the start of construction and prior to applying for any National Pollutant Discharge Elimination System (NPDES) permit in order to receive a NPDES Permit. A well-developed SWPPP is the first line of defense for sediment and erosion control. The first purpose is to “identify potential sources of stormwater pollution on a construction, industrial and/or municipal site.” 1 In order to prevent illicit discharges, yo...
by Matthew Trygg // 2020-08-04Read More
Karst Topography: Sinkholes
Several challenges arise when building in an area that has Karst topography. These areas prominently occur in areas where the bedrock has carbonate-rich rocks like Limestone, Dolomite, and Gypsum. These rocks under the right circumstance will dissolve and leave voids beneath the ground surface. A sinkhole occurs when the soils above the void can no longer support their weight. Sinkholes can happen slowly or rapidly. Before constructing in these locations, subsurface soil investigations a...
by Rick Jackson // 2020-08-03Read More
Temporary (temp) stabilization is any material or product that can be applied to disturbed ground and stockpiles, for erosion control protection. Temporary stabilization is intended to counteract the erosive influences of rain, snowmelt and wind. Without temp stabilization on disturbed areas, erosion and stormwater runoff are significantly more likely to occur. Erosion and stormwater runoff can lead to sediment build-up. Sediment can carry many pollutants which flow into the streets and e...
by Brian Hartman // 2020-08-03Read More
When and When Not to Use Dust Palliative
The main purpose of a dust palliative is to temporarily prevent erosion and provide temporary stabilization for dust. Dust palliatives are often used in the construction industry and can be used in a variety of climates such as the desert here in Arizona. Proper research should be done to determine the correct palliative for your climate. Due to the lack of rain in Arizona, the soil is very dry and often becomes airborne once the material on a construction site is disturbed. County regulators...
by Brooks Morse // 2020-08-03Read More
Perimeter Erosion Controls
Arguably one of the most important Best Management Practices (BMP) on a construction site, whether residential or commercial, is the installation and maintenance of perimeter controls. Perimeter controls may vary depending on the needs of the construction site (ie. Silt fence, fiber logs, hay bales, trackout control device, etc.) Perimeter controls are generally the first temporary BMP to be installed and the last to be removed. It is important to thoroughly inspect perimeter BMP’s to ens...
by Johnathan Clayton // 2020-08-03Read More
Wondering About Social Distance?
This Q1 2020 article will diverge from the normal focus on strictly stormwater information. In the wake of the Covid-19 pandemic there are many questions and uncertainties as we all look for answers. One recommended social practice now being accepted worldwide is Social Distancing. The following information comes from a New York Times article titled “Wondering about Social Distancing” by Apoorva Mandavilli on 16-MAR-2020. Here in the US our President has now endorsed a voluntary practi...
by Mark Hubbard // 2020-08-03Read More
The Illinois Urban Manual
The Illinois Urban Manual is a technical reference for those involved in the inspecting and/or installing Best Management Practices (BMPs) for soil and erosion control on construction sites in the state of Illinois. The manual has been put together and updated by the state of Illinois and the public. The state entity includes the following public agencies representing the entire State of Illinois: AISWCD, IEPA, Soil & Water Conservation Districts (SWCDs), Illinois Department of Agricu...
by Matthew Trygg // 2020-08-03Read More
Navigating Local, State and Federal Regulations
States are required to follow the National Pollutant Discharge Elimination System (NPDES) permit program set by the Environmental Protection Agency (EPA). The EPA has authorized most states to perform their own permitting, administrative and enforcement aspects of the program (NPDES, 2020), however, regulations do not stop there. In Texas cities and counties are also allowed to create and enforce their own set of ordinances that are as or more stringent than the Texas Pollutant Discharge ...
by Haley Daily // 2020-08-03Read More
Floating Silt Curtains
The main purpose of BMPs (Best Management Practices) on a construction site are to keep lakes, rivers, streams, and wetlands free of sediment pollution. Sediment pollution can negatively impact the environment in many ways, including the degradation of plant and animal life. Turbid water blocks sunlight from reaching plant life, and also prevents fish and other animals from seeing their food. In return, this completely disrupts the food chain which can severely impact the natural habitat....
by Brian Hartman // 2020-07-30Read More
Temporary stabilization is a soil stabilization measure that is generally used for disturbed areas of a construction site that have a planned period of inactivity. In Florida, the Construction General Permit (CGP) calls for temporary stabilization to be implemented when an area of disturbed soil will not be active for a period of 7 days or greater. There are many ways to achieve temporary stabilization, some of which include: seeding, sodding, mulching, soil binding agents, erosion contro...
by Johnathan Clayton // 2020-07-30Read More
Why Should I Care about Concrete Washout?
Water used in the concrete washout process has a high level pH, that pH level can be near 12, which is essentially the same as liquid drain cleaner, ammonia or other household cleaning detergents. The safe pH ranges for aquatic life habitats are 6.5 – 9 for freshwater and 6.5 – 8.5 for saltwater. Another issue with concrete washout is it has other toxins include Aluminum, Barium, Chromium, Hexavalent Chromium (Chromium 6), Copper, Iron, Magnesium, Manganese, Nickel, Potassium, Selenium, Sodiu...
by Matthew Trygg // 2020-07-30Read More
Non-Structural Approach to Stormwater Pollution Prevention
A Stormwater pollution prevention plan is essential for the development of measures aimed at the elimination of illicit discharges. Although most of the attention toward pollution prevention in the Stormwater Plan is given to the structural BMPs, a plan for the use of non-structural BMP can also play an integral role. One such example is the vacuum street sweeper. While we are all familiar with the street sweepers utilized by most cities and towns, that same methodology of pollution c...
by Mark Hubbard // 2020-07-30Read More
Steep Slope Stabilization
Slope stabilization techniques have been around for a long time. However, what many do not realize is that not all stabilization techniques are suitable for every situation. Most traditional methods, i.e., natural fiber stabilization blankets, are only suitable for shallower slope (3:1 and shallower)1 situations. With a greater slope, the demands on the stabilization method increases as the water velocities will also increase. With the heightened erosion potential, many commonly used erosion...
by Rick Jackson // 2020-07-25Read More
Is Housekeeping that Essential to Stormwater?
A common question with the NPDES inspection process regards trash or construction debris and if it relates to the stormwater plan. It absolutely does! Trash and debris directly affect the stormwater plan and is a specific requirement in state Construction General Permits (CGP) to maintain. Most often attention is given to sediment and hazardous material to determine if a site is in compliance, these are only part of staying in compliance as there are many items throughout state CGPs th...
by Brooks Morse // 2020-07-25Read More
In 5 Years
Five years ago, Cherie Koester left a prominent job with Maricopa County to start her own business. From her residence in Queen Creek, Koester founded Earthworks Environmental LLC. As the woman- and minority-owned environmental consulting firm celebrates its fifth anniversary, the Mesa-based company now boasts 36 employees and almost 800 projects across the country. “While our 5-year celebration is local, I’m extremely proud of my staff for the expansion we’ve made across the country,” ...Read More
2019 Quarter 3 Newsletter
2019 Quarter 3 Newsletter Click the link above for the PDF version of our 2019 Quarter 3 Newsletter.
2019 Quarter 2 Newsletter
2019 Quarter 2 Newsletter Click the link above for the PDF version of our 2019 Quarter 2 Newsletter.