Winter is officially here! Well, not officially, but the time to stabilize construction sites for the winter is here!  The winter stabilization window listed in the Rainwater and Land Development window is November 1st through February 29th. Any areas that have exposed soil on an active construction site will need to be stabilized for the winter if the area will be dormant for 21 days or more over the winter. This month’s development digest on winter stabilization is a basic overview on why this BMP (Best Management Practice) is important, and the specifications of this stabilization practice.
Soil pollution is an issue that greatly affects the water that runs through Warren County. Soil pollution can be greatly increased in the winter due to the large amounts of snow, and melting of that snow, that creates water runoff. BMPs are practices we can put in place to minimize the risk of soil pollution. Winter stabilization is an important BMP that can help keep the soil out of the waters.

So, what exactly does winter stabilization entail? Winter stabilization can involve two different methods. The first method involves planting a dormant, cool season grass that will survive the winter and start its growth in the spring. Putting mulch down is also a necessary step to allow this method to be effective. The second method is to only put mulch down and not worry about the seed. This method may be more applicable if earthwork will resume directly at the end of winter when work starts back up. Both methods involve mulch, which is important because mulch provides a barrier between the stormwater and the exposed soil that help to keep the soil in place. Below are examples of types of mulch and types of grass seed that can be used.
 

Types of Mulch:        

• Straw                                                                                                
• Straw matting
• Wood chips
• Shredded woody material
• Pine needles
• Compost

 
Grass Species:

• Tall fescue
• Annual Ryegrass
• Perennial Ryegrass
• Kentucky Bluegrass

 
 
More information on temporary seeding throughout the year can be found on Table 7.8.1 of the Rainwater and Land Development Manual. For an area to be considered stable, 70% of the area should be seeded and mulched.
Stabilizing a site during the winter is the best method to prevent erosion and sediment runoff during a time of the year when work may not be happening. At the very least, dormant areas with exposed sediment should be mulched during the winter months. Further information on temporary stabilization techniques can be found on the Rainwater and Land Development Manual. Further information on stabilization regulations can be found in the Ohio Construction General Permit.
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Have questions on the topic of winter stabilization? Please feel free to reach out to our office through email at [email protected] or call us at (513) 695-1337.  

​You may have heard lately that Ohio is in a drought. A recently released drought map indicates Warren County to be in a severe to extreme drought. During these dry times, your construction site may welcome the lack of rain as dry sites can be easier to move around on and experience fewer issues with sediment and erosion control. However, we can’t get complacent on sediment and erosion control. The battle must go on!

In this month’s Development Digest, we will discuss remaining vigilant during dry times by having a routine dust control program in place, as well as making sure site BMPs are ready to go for the big rain. Dust can be a real problem during times of drought. So much so, that Soil and Water Conservation Districts were established to combat this issue, after the Great Dust Bowl of the 1930s. Poor farming practices, dry conditions, high winds, and plowing all combined to stir up the earth and create massive dust storms throughout the Midwest. President FDR signed the Soil Conservation Act of 1935 to protect our Country’s soil and water resources. This led to the establishment of the Ohio Soil and Water Conservation Commission (OSWCC) in 1941, which allowed funding to create Soil and Water Conservation Districts throughout the state. On construction sites, we often focus on keeping sediment contained during rain events, but soil loss can also occur during a drought. That’s why it’s important establish a dust control routine to keep sediment contained. Dust can be a real problem, as it is considered an airborne contaminant. Nearby existing homes and property can be covered in dust. It can become a public health concern when residents have trouble breathing. Our office has been receiving complaints from many sites throughout the county and we have been working with site contractors to ensure dust control measures are being enacted. 
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This can become a sleeping monster if dust control isn’t implemented. During times of extended drought, the ground becomes drier and harder. Especially in Warren County where much of the soil is clay, the ground can become like an impervious surface when it is compacted, dried and hardened. So, when it does eventually rain, the first initial downpour will likely run off the surface quickly, like it would on pavement. To further compound the issue, vehicles driving around on the site stirs up the sediment, creating dust clouds that will settle on the hard ground.  This fine-grained dust that settles accumulates almost like the regolith and dust on the surface of the moon. We are seeing anywhere from 1 to 3 inches of dust settled on some sites lately. 

4. Stone- Install crushed stone on graded roadways with construction traffic.
5. Barriers- Snow fencing or other suitable barriers may be placed perpendicular to wind currents to control air currents and blowing soil.
6. Calcium Chloride- the chemical may be applied by mechanical spreader as loose, dry granules. Follow manufacturer’s specs.
7. Operation and Maintenance- Repetitive, routine treatment of dust control practices.
8. Street Cleaning- Remove any settled dust from paved areas with a routine street sweeping schedule.

​Due to the recent drought, this is a great time to think about dust control. It looks like we will be getting some rain soon, so keep these practices in mind for the next dry time! If you have any questions regarding dust control you can contact us at the Warren County Soil and Water Conservation District website https://www.warrenswcd.com/ or by our phone number at (513) 695-1337.    

Additional Resources
 
Ohio EPA Rainwater and Land Development Manual. Chapter 7 Soil Stabilization – Dust Control: https://epa.ohio.gov/divisions-and-offices/surface-water/guides-manuals/rainwater-and-land-development?msclkid=cb5f60f4b48d11ec8b5ece1ef5e16d3c

​Sediment basins are designed to trap sediment from a construction site. If not maintained properly the basin can become filled with sediment and algae. While keeping sediment and algae out of the basin may seem like an impossible task, there are steps that can lessen the buildup and costly maintenance associated with dipping out or treating the basin. The following article covers sediment basin function, maintenance, and considerations to reduce algae.
Sediment Basin Basics
A sediment basin is a settling pond. By slowing down the flow of sediment-laden runoff, solids can settle out and sink to the bottom of the basin. The sediment basin is constructed as a first step, prior to land disturbing activities. The settling basin is usually converted to a wet retention basin or a dry detention basin at the end of the construction project. During construction, the basin functions for sediment control while after construction, the basin functions for stormwater flood control and water quality improvement practice.
How it Works 
As construction site runoff flows into the basin its flow rate is slowed on reaching the basin. Heavier sediment particles sink to the bottom while clean water remains in the top dewatering zone. As the water makes its way to the outlet a skimmer pulls water from near the surface and directs it through the principal spillway. During extreme rain events water would build up in the basin then flow through the riser and the principal spillway.

Maintenance for Proper Function and Control of Algae
For a basin to function, accumulated sediment must be removed from the sediment storage zone once it exceeds 50 percent of the minimum required sediment storage design capacity and prior to the conversion to the post-construction practice. Excess sediment in the basin decreases the depth of the dewatering zone, brings in other potential pollutants, such as nutrients. Sediment buildup also increases the maintenance required to keep the basin functional.  
The shallow water also allows additional sunlight to make its way to the bottom of the basin further warming the water. Shallow water promotes the growth of vegetation, algae, and mosquitos. Algae can increase maintenance needs by creating additional solids that settle to the basin bottom and fill the sediment storage zone with muck. Some blue green algae can also produce toxins making the water unsafe.
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Prevent Early Fill-up of the Sediment Storage Zone
The following steps can help minimize maintenance needs while keeping the basin functional.

1. Stabilize the inner bank of the basin as early as possible utilizing grass seed and straw matting.
2. Remove sediment from inflow into the basin by utilizing stabilized grass swales, silt fence, or filter sock and other best management practices on the construction site.
3. Excavate the construction site in phases so that less of the dirt is exposed and subject to erosion.
4. Keep the disturbed area of the site as small as possible.
5. Stabilize the construction site as soon as possible.
6. Have a pond management company treat algae blooms before they become severe.
7. Dip sediment once it exceeds (50%) of the minimum required sediment storage and prior to conversion to post-construction.

Prevention of excess sediment in the basin is often more cost effective than bringing in heavy equipment to dip out the basin and then hauling off the sediment. These steps can also reduce resident and local homeowner association complaints down the road.
 
Additional information can be found in the Rainwater and Land Development Manual, Chapter 6

​Questions? Contact our office at 513.695.1337

​In an episode of Seinfeld, Newman is quoted as saying “The mail, it never stops Jerry!” The same can be said for maintenance of sediment & erosion control measures (SECMs) on construction sites; it is a never-ending battle, and it never stops!
 
Your project should have a stormwater team established to ensure that all SECMs are inspected once every 7 calendar days and after every > 0.5-inch rain event per 24-hour period by the end of the next calendar day (per Ohio EPA Construction General Permit requirements). The stormwater and resulting sediment-laden runoff, never stop. So that’s why it’s important that we remain vigilant and maintain the SECMs until the site is stabilized with grass.
 
Warren County SWCD conducts monthly site inspections to help your crew identify failing or missing BMPs to help you stay compliant with the Construction General Permit. When we encounter a project that has done a great job on installation and maintenance of the SECMs, we like to highlight it in our Development Digest for a job well done.
 
This month, we call attention to the Eastern Gas Transmission and Storage, Inc. (EGTS) Lebanon Compressor Station HP project in Clearcreek Township. EGTS boasts a robust environmental compliance division as well as an on-site stormwater team that has been great to work with. The stormwater team has followed the Stormwater Pollution Prevention Plan (SWPPP) to make sure the SECMs are properly installed and maintained.
 
Not only does the site exemplify superb examples of proper SECM installation, maintenance, and an inspection routine, but they also place an emphasis on employee safety. The focus on safety really demonstrates how it’s not just about protecting the environment, but also the people that work together to achieve a common goal.
 
The site is not without its challenges however, with a wetland conveniently nestled between construction areas. The stormwater team has highlighted the importance of protecting the wetland to prevent sediment from filling it in. Most of Ohio’s wetlands have been lost since the days when Ohio was a frontier state. EGTS understands the importance of protecting the ones we still have left. But don’t take my word for it! Hear it from the pros at EGTS:

​In closing, we at Warren County SWCD understand that development does not come without risks to the environment, that’s why it’s important that development happens in an environmentally conscious way. So, well done EGTS. May all other construction sites follow your lead!

​​Questions about BMPs?  Call Warren Co SWCD offices at (513) 695-1337

Fast moving water can cause a LOT of damage! Many problems can arise from water flowing at a high velocity. This is especially the case when talking about a high flow rate in concentrated areas such as ditches or swales. Erosion is an issue that can result from the high velocities that may occur in ditches or swales, and so it is important to find ways to mitigate the erosion in the best way possible. Check dams are a great option that can be installed in ditches and swales to decrease the water velocity and in some cases keep sediment from washing downstream.

​Check dams are constructed structures built up as a wall in a flow path that serves the purpose of slowing down water velocity. Many check dams consist of 4–8-inch stone and are no higher than 3 feet tall and are constructed along the width of the swale/ditch. Check dams can also be constructed of material such as compost filter sock. As mentioned above, check dams can also serve the purpose of keeping sediment from washing downstream. However, not all types of check dams are good for sediment control. Rock check dams are an effective way to slow down velocity and prevent erosion, however, rock is not an effective method to keep sediment from washing away due to the pore space in the material that sediment can wash right through. Filter socks are designed to keep sediment from washing downstream, and so if the goal is to slow the velocity of the water AND keep sediment in, then a filter sock check dam might be the best option.  

Maintenance Considerations:

• Per the Rainwater and Land Development manual, once sediment has built up to one-half the original height of the check dam, the sediment should be removed.
• Removal of the check dam should occur once earth disturbance has ended and the upland area has been stabilized. Once the check dam has been removed, the area should be graded and seeded to match the surrounding area per the design.
• Routine inspections are also a great way to ensure the check dam is working effectively.

 
For more information on the design criteria and specifications about check dams, please visit the OEPA Rainwater and Land Development Manual chapter 5.1. For regulations regarding construction and earth disturbance in Ohio please see the OEPA NPDES Construction General Permit.

How does a concrete washout area promote workplace safety?
Concrete washout is a caustic and corrosive waste material with a pH of around 12. If an employee is exposed to washout, they can suffer serious skin irritation, chemical burns, and eye damage. Additionally, concrete washout contains toxic metals like Chromium, Nickel, Vanadium, and Zinc. Exposure in large amounts to these metals can cause long-term damage to the brain, lungs, kidneys, liver, and other important organs. Keeping waste contained to one or two designated areas will help minimize exposures and promote workplace safety.
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What kind of maintenance does a concrete washout area require?

• Inspecting the area regularly to ensure no leaks occur
• Emptying the area of waste before it reaches capacity
• Cleaning up spilled or improperly disposed of slurry

 
Note: Washout waste is also created when using mortar, plaster, stucco, and grout and should also be disposed of properly.
 
Additional Resources
US EPA Concrete Washout Fact Sheet
OSHA Concrete Hazards
OEPA Rainwater and Land Development Manual
Ohio EPA NPDES General Construction Permit (OHC000006)

BMP Blasts are issued every three months to highlight a sediment and erosion control best management practice. These blasts are designed to provide helpful insight and tips for properly designing, installing, using, and maintaining the control measure.  

Where and why is inlet protection required?
 
Inlet protection is required on any storm drain at risk of receiving construction site run off. That said, there are limitations to the power of inlet protection. These controls are only designed to manage sediment from a drainage area of one acre or less. If greater than 1 acre of land is draining to one inlet, additional practices such as sediment traps or basins may be required. You may be thinking, “but, I have silt fence and a basin with a skimmer already!”  Unfortunately, no one practice is 100% effective when it comes to sediment removal; they each have different strengths and weaknesses. For example, inlet protection has a limited ability to remove silts and clays but can effectively capture larger sand-size particles. The combined effect of each BMP helps to provide maximum sediment removal from storm flows prior to off-site discharge.
 
In other words- perimeter controls, inlet protection, and a basin with a skimmer are likely all required (depending on the site and area of disturbance).

​Should I have inlet protection listed on my SWPPP?
 
Yes! Inlet protection must be shown on the stormwater pollution prevention plan.
While most contractors are familiar with the need for inlet protection, it is important that this is noted on plans to ensure any operator on-site is aware of the requirements and a proper maintenance schedule can be in place. The plan will also show the location all of these “at-risk” inlets so that protection gets installed on all drains and inspectors on-site can identify the location of these areas.
 
Furthermore, it is important to show where these practices will be located in the plan review process to ensure that the drainage area is sized appropriately for the practice.
 
There are certain considerations for placement as well. For example, practices that operate by blocking water from entering storm drains almost completely prevents sediment-laden discharges to entering the conveyance system, but they often result in ponding water. This ponding may be important to consider if these practices will be used on roadways that could flood during heavy rainfall.
 
Are there different types of inlet protection?
 
There are various methods of inlet protection specified in Chapter 6 of the Ohio Rainwater and Land Development Manual. Each method utilizes a combination of stone, wire mesh, and/or geotextile to filter sediment. Alternatively, pre-manufactured inlet protection devices may be used (and reused for the lifetime of the product). 

What kind of maintenance do inlet filters require?

• Regular sediment removal (when 50% capacity of control device is reached)
• Removal of waste/debris
• Monitor for flooding and ponding
• Repair/replace torn fabric
• Resecure fabric/devices/curb stops that have been moved out of place
• Removal of controls at the end of construction activity once all contributing drainage areas have been stabilized

 
Additional Resources
OEPA Rainwater and Land Development Manual
United States EPA Storm Drain Inlet Protection Fact Sheet
Ohio EPA NPDES General Construction Permit (OHC000006)

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Sediment and erosion control maintenance needs are inevitable on construction sites.
With the nature of construction activity and rainfall events, it is nearly impossible for controls to stay in perfect condition throughout the entire process. However, the more that your team stays on top of maintenance needs and acts proactively, the better the chances are to keep controls functioning and keep your site in compliance.
 
General BMP Inspection Tips: The best way to stay on top of maintenance needs is to conduct routine inspections according to the guidance provided in the Rainwater and Land Development manual. Controls should be inspected daily for general condition and effectiveness. They should also be inspected after each rainfall event and during a prolonged rainfall. If controls aren’t being inspected on a regular basis, it is easy for small maintenance needs to compound and become larger issues over time.
Below are 7 common BMP maintenance needs our urban inspectors see out on site and some tips for staying on top:

1. Downed Silt Fence ​

​Fix Tips: If silt fence is downed, it may be able to be retrenched and wrapped around the stakes again. Ensure silt fence is properly trenched and pulled taught.  If the geotextile material has been damaged, it will need replaced entirely. 

​Fix Tips: If using a basket or dam style inlet protection, ensure that capture device is secured underneath grate to prevent getting pulled into catch basin or swept into roadway. For curb inlets, ensure that curb stops are installed along rear of the grate to ensure that water cannot enter through the sides or top of the inlet.

​Fix Tips: Replace socks that have been torn or damaged beyond repair. If socks have just become flattened, refill with compost material until they are returned to the appropriate diameter. Encourage your team to use established construction entrances to prevent running over the socks. If the socks are moved for utility or other work on the lot, ensure that they are replaced in the appropriate location as soon as feasible. 

​Fix Tips: Sweep the streets any time you notice a significant amount of tracking occurring. Establish a routine street sweeping schedule to prevent heavy accumulation on roadway. Ensure other practices (such as silt fence or filter socks, proper construction entrances) are in place and functioning to help stop sediment tracking in the first place. 

​Fix Tips: If you notice sediment is overtopping the berms, the sediment may need to be dug out away from the berm area. It’s best practice to keep the sediment deposit level below ½ of the height of mulch berms or silt fence. If a heavy rainfall knocks down a portion of the berm, make sure that berms are built back up to meet the specifications outlined in the RWLD manual. 

​Fix Tips: ODOT 1/2s should be used for construction entrances. Smaller gravel tends to get swept into the roadway with sediment. If the incorrect aggregate is used, this will need to be revised to prevent off site tracking. If a construction entrance is regularly used, the aggregate may need to be replaced to provide ample area to kick sediment off wheels. 

​Fix Tips: Concrete washout pits should be emptied on a regular basis to prevent overflowing. If pits are dug out in the ground, they should be lined with a tarp to prevent leaching into bare soils. If the liner gets damaged or rolled up, it needs to be readjusted or replaced. The pit should have four walls around (typically lined straw bales). If the walls of the pit are compromised, they need to be rebuilt or replaced. 

Greg Fuller, Project Manager, and his team at Ryan Homes have done a great job of staying on top of sediment and erosion control maintenance needs in Villages of Classicway 7B in Hamilton Township. From the beginning of the project, Greg has kept in contact with our team at WCSWCD to address any deficiencies on site in a timely manner.  The team at Ryan Homes keeps a plan set posted in the model home on-site with pins to denote areas where BMPs require maintenance. With all the different tasks to manage on a construction site, this type of mapping can be a helpful tool and visual for teams to prioritize areas that require the most attention and prevent maintenance needs from progressing into larger problems.  Ryan Homes also had a great system for record keeping. The inspection logs were neatly organized and stored in binders in a safe, dry area. This is crucial as monthly site inspection logs are to be kept for 3 years according to the Stormwater Pollution Prevention Plan requirements. 

These are the results of staying on top of BMP maintenance!