I’m just clearing. Do I need a permit?
 
The answer is likely yes! In Warren County, an Earth Disturbing Permit (EDP) is required for any project expected to disturb a total area of an acre or more of land. Removing trees with the entire root ball results in land disturbance and exposed soil.
 
Clearing involves the cutting and removal of trees, brush, and other above ground material while grubbing is the removal of roots, stumps, and other material below the existing grade. Regarding an EDP, it does not matter whether the vegetation was naturally occurring or intentionally planted.
 
If you think of this in terms of one tree, it might not seem like a huge concern, but when you think of this type of tree clearing on a large scale (i.e. an acre or more of tree clearing), it can lead to quite a bit of disturbed soil and potential for sediment-laden discharges from the site during rainfall events.
 
Are there any other restrictions for clearing?
 
Yes, depending on when and where you are developing.
 
Tree clearing must not occur between April 1st and September 30th without first coordinating with the Ohio Department of Natural Resources- Division of Wildlife (ODNR-DOW) and the U.S. Fish and Wildlife Service- Ohio Field Office (USFWS-OHFO).
 
Native bat species roost and raise their young in trees all throughout Ohio during this time each year. Unfortunately, all bats in the state are experiencing population decline and have become protected by law in some way. The U.S. Endangered Species Act of 1973 is periodically updated to protect endangered and threatened flora and fauna across the country. Federally endangered species in Ohio include the Indiana Bat (Myotis sodalist) and Northern Long-Eared Bat (Myotis septentrionalis). If your project calls for tree-clearing activities during this five-month window, the ODNR and USFWS will recommend surveys be conducted to determine if the proposed area will negatively impact the bats. If there are no hibernaculum or bats identified during the survey, it may be safe to proceed with tree clearing.

For earth disturbing activities immediately adjacent to surface waters of the state, the Ohio Environmental Protection Agency (OEPA) requires that, if feasible, a 50-foot buffer on either side of the ordinary high-water mark must remain undisturbed. Trees and brush along a water bodies’ edge provides significant stream bank stabilization. If a natural buffer cannot be maintained, land must be temporarily stabilized within two days of the most recent disturbance (if the area will remain idle for more than 14 days) and permanently stabilized within two days of reaching final grade.
 
Whenever possible, we strongly recommend preserving trees during land development as they prevent erosion, reduce runoff rates, and increase property value. For guidance on tree and natural area preservation, refer to Chapter 7.3 of the Ohio Rainwater and Land Development Manual.
 
Additional Resources
USEPA Preserving Natural or Existing Vegetation Fact Sheet
Ohio 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)

​

Fall-time in southwestern Ohio is simply wonderful; the weather starts to cool down and the trees transform into a lovely autumn palette. Around this time of year, we like to remind developers to continue seeding as much bare soil as possible before winter turns the corner.
Soil erosion remains an area of concern for earth disturbing work throughout winter as melting snowfall transports sediment into our local waterways. According to the Ohio Rainwater and Land Development Manual, soil stabilization is the most effective way to minimize sediment erosion from construction sites (over >90%). We mean it when we say seeding and sod installation is music to our ears!

Temporary seeding (which must be applied to bare soil where additional work is not scheduled for more than 14 days) may continue until November 1st. Especially through late fall, we recommend monitoring and maintaining seeding efforts until an overall vegetative density of >70% has been achieved. Fall-time seeding species include Rye, Tall Fescue, Annual and Perennial Ryegrass, Creeping Red Fescue, and Kentucky Bluegrass. A layer of mulch (straw, wood cellulose fiber, and/or mulch matting) must be applied during or immediately after seeding. During more favorable seeding times of year, mulching may not be necessary but late fall weather warrants the extra protection.

The window for permanent seeding (which must be applied to bare soil at final grade that may be idle for over 1 year) has now closed (March 1st through September 30th). Click here for our guide to dormant seeding during winter months. Traditional permanent seeding efforts may germinate during late fall, but they are unlikely to survive the winter.
​
Spotlight Example from the Field: Seeding Before Winter
Ryan Wilms and his team at Cincinnati United Contractors have been working on improvements at Green Bay Packaging in Lebanon, OH. During routine inspections, we noticed their team’s excellent pre-winter stabilization. Having this steep slope stabilized now will set them up for success throughout winter. This also allows for more efficient sediment management throughout the rest of their project.

What if temporary/final grading work took longer than expected and you missed the seeding window? Although the disturbed areas cannot be traditionally seeded after the windows have closed, bare soils must be mulched or dormant seeded.

For more specific technical guidance and specifications, please review the most recent OEPA Construction General Permit (OHC000006), the Rainwater and Land Development Manual, and the Stormwater Pollution Prevention Plan (SWPPP) for your site.

Additional Resources
Construction Site Winterization – Development Digest
Rainwater and Land Development Manual
Ohio EPA NPDES General Construction Permit (OHC000006)
Seeding Tables – USDA NRCS

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!

A skimmer device is a dewatering measure that secures to basin outlet structures during construction activity. There are several different available models that are accepted by the Ohio EPA. Some of the commonly used models include Erosion Supply and Company (ESC) Skimmer, Delaware Department of Transportation Skimmer, Faircloth Skimmer, Innovative Applied Solutions (IAS) Skimmer, and the Rymer Marlee Float Skimmer (pictured above).

What is the point of using a skimmer? Let’s start with the principle of sedimentation. Sedimentation is the process of sediment particles settling out of a fluid media and precipitating against a solid surface. Stormwater basins hold discharges to allow the suspended sediment to descend in the water column and settle on the floor of the basin.

​ Multi-stage outlet structures are designed to accommodate different levels of water during different rainfall conditions and manage water quality post-construction. However, these structures are not designed to manage the excess sediment that can result from earth disturbance during construction.

 A skimmer structure connects to the outlet orifice and floats on the surface of the water.

When we revisit the concept of sedimentation, that means that the skimmer structure should be intaking the cleanest portion of the water column.This means that less sediment will be traveling through the outlet structure and pipes. This reduces the amount of built-up sediment that can occur in those structures and the amount of maintenance required post-construction. Additionally, this reduces the amount of water that is flowing from the basin directly into streams and other natural waterways.

Can’t I just put some rip rap at the basin outfall instead?  While rip rap and rock check dams can certainly help to kick some sediment out of runoff, they are not intended to be used as sediment control measures, because a great amount of sediment can still infiltrate through the gaps in the aggregate. Rather, these controls are considered erosion control measures primarily designed to slow the velocity of water. Adding aggregate at the outfall will help to prevent erosion from the concentrated flow exiting the basin but will not replace the need for a skimmer.In addition, if you are not using a skimmer device on the basin and only using controls at the outfall, the basin is being dewatered from a more turbid portion of the water column rather than the cleaner water surface. Therefore, it would take even more work to filter out the sediment at the point of the outfall rather than at the source.Lastly, stormwater pollution prevention plans are specifically designed and engineered to dewater at these elevations and through these devices to meet permit requirements. When plans are not implemented as designed, it can not only present structural complications and present risk to other areas of the project, but it is also a direct violation of the environmental protection regulations in place to safeguard natural ecosystems.

How do you design a basin with an appropriate skimmer device?

There are several resources that can help with determining the appropriate skimmer for dewatering a basin. One of the best places to start is Ohio EPA’s sediment basin and dewatering compliance tool:https://epa.ohio.gov/static/Portals/35/storm/Sediment+Basin+Compliance+Tool+(Printer+Friendly).xlsx  In case you are not familiar, this comprehensive spreadsheet not only helps to ensure that the sediment basins listed in the SWP3 meet the sediment storage and dewatering volume permit requirements, but it also helps to provide guidance and resources for skimmer orifice sizing and dewatering time compliance.  Depending on the skimmer model, the spreadsheet will direct you to the manufacturer-specific calculator tools for a simple way to meet design standards.                                                    ​

Installation will depend on the skimmer model and the basin outlet design. However, the skimmer will directly attach the orifice via a coupling. If the basin is a detention pond and has a lower-level water quality orifice that will have gravel and perforated pipe post construction, this will need to be closed off during construction to allow collected water to enter through the skimmer device instead. Maintenance of the skimmer is essential during construction. You will need to ensure that the skimmer stays properly attached to the outlet for the entire duration of the project. Skimmers may also get stuck on the floor of the basin during periods without rainfall. To prevent this from occurring, the skimmer can be elevated on a surface of aggregate, cinder blocks, or bricks. If the skimmer does not seem to be performing optimally, debris and built-up sediment may need to be periodically removed from the orifice plate and screen. Lastly, the area around the outlet and skimmer needs to be free of excess vegetation to prevent clogs and to prevent the skimmer from getting caught in the vegetation and becoming detached or elevated above the surface of the water.

Does the skimmer stay on forever? Nope! Once construction is complete and the entire project site is stabilized with vegetation, the skimmer device can be removed and replaced with the permanent outlet structure. 

BMP Spotlight Example from the Field: Skimmers
Branson Staller and his team at SiteWORX have been working at Project Care in Mason, Ohio[BJA2]  to construct a new Mercy Hospital facility. During routine inspections, we noticed their team’s prompt basin and skimmer device installation. Having the skimmer on the outlet from the get go has made for more efficient sediment management throughout the project.  

It’s here! The OHC000006 General Permit can be found on Ohio EPA’s website: https://epa.ohio.gov/divisions-and-offices/surface-water/permitting/storm-water-discharges-from-small-and-large-construction-activities--general-permit
​
RENEWAL PROCESS
If your site is currently covered under the previous iteration of the Construction General Permit (OHC000005), that coverage will be terminated 180 days after the effective date of the new permit (April 23, 2023) if you do not submit a renewal application. You can submit the renewal application through the Ohio EPA eBusiness Center here: https://ebiz.epa.ohio.gov/  
​
Once you open your active permit(s) in STREAMS, you will click “Renewal” in the action drop down list as shown in the screen shot below to bring up the renewal application form. 

​If your project is complete and will not require renewed permit coverage, you need to submit a Notice of Termination (NOT) application form through Ohio EPA’s eBusiness Center by selecting “Terminate” in the dropdown list rather than “renewal”.

PERMIT UPDATES
One of the first (and obviously most important) changes to note in the OHC000006 permit is updating “stormwater” to one word instead of two. The Table of Contents was also updated and is now hyperlinked. Additional numbering has also been provided in longer sections to make navigation easier. 

POST CONSTRUCTION RERQUIREMENTS
Extended Detention Requirements: An additional volume equal to 20% of the WQv must be incorporated into the BMP for sediment storage.

Infiltration Practices Requirements: The design infiltration rate values must be derived from site-specific measurements obtained through field tests of the in-situ soil for practices designed to infiltrate the WQv (table 4a and 4b).

Pedestrian Trails: Pedestrian trails may implement post-construction BMPs in compliance with the current version of the ODOT Location and Design Manual, Volume Two Drainage Design (Ohio EPA accepted alternative to conditions of the permit).

Redevelopment Projects (Encourages the redevelopment of areas that were not previously subjected to WQv). Must meet one or both criteria:

• A 20% net reduction of site’s volumetric runoff coefficient with soil restoration or the use of a green roof
• A portion of the site treated using a practice meeting Table 4a/4b criteria for which the WQv (see Equation 1) Alternative Post-Construction BMP

This section does not apply to previous development that was obligated to obtain CGP coverage and provide management of the WQv under previous generations of this general permit (i.e., after April 21, 2003). This is in place to prevent a reduced level of treatment.

Alternative Post-Construction BMPs:

• All alternative post-construction BMPs require EPA approval and must fall within certain technical criteria outlined in the section:
• Practice must be capable of providing sustained, long-term stormwater treatment.
• The stormwater treatment efficiency must be equivalent to that in table 4a and 4b (includes laboratory, field testing).
• The discharge rate from the practice shall be reduced to prevent erosion and protect physical and biological stream integrity.
• New permit allows both pretreatment and primary practices to properly reference the BMP testing criteria and address changes to Washington TAPE and STEPP. 

SEDIMENT BARRIERS
Language to clarify “tubular barriers” (i.e. filter sock, silt sock) are allowable practice and referenced in the Rainwater and Land Development Manual.

STREAM SETBACKS
Ohio EPA strongly recommends 50ft buffers to be maintained around surface water (including wetlands).

ELECTRONIC RECORD KEEPING

• Electronic records cannot be modified without digital audit trail.
• Modifications and people responsible for making modifications must be documented.  
• Systems need to have clear instructions for users to ensure proper use.
• Electronic records (NOI, SWP3, coverage letter, and inspection reports) must be made readily available on-site (must be able to furnish immediately for authorized representatives).

NOTICE OF TERMINATION REQUIREMENTS
Permit remains in effect until a signed Notice of Termination (NOT) form is submitted and permit coverage is terminated by the Ohio EPA.

BIG DARBY CREEK PERMIT (Does not Apply to Warren County)

• New permit prioritizes infiltration practices to address WQv.
• An alternative discharge performance standard of 50 NTUs is provided for sediment ponds.  
• Only jurisdictional ephemeral streams are subject to riparian setback requirements.

OLENTANGY RIVER PERMIT (Does not Apply to Warren County)
Only jurisdictional ephemeral streams are subject to riparian setback requirements.
​

As defined by the Federal Environmental Protection Agency, Low Impact Development (LID) refers to a variety of practices designed to mimic natural drainage to manage stormwater flow. The overarching goal is to minimize the impact of development on the natural landscape and environment. In contrast to high impact development with mostly impervious surface and grey infrastructure, these practices encourage stormwater percolation into the soil. In addition to managing stormwater volume, this helps to filter out pollutants that may be picked up by stormwater as it makes its way to natural waterways.
 
What are the Benefits of LID? 
Economic

• cut costs associated with traditional infrastructure materials (such as curb, pavement, basin outlet/inlet structures, pipe conveyance systems, culverts, etc.)
• reduce clearing/grading costs (less disturbance = less of this work)
• increase value of residential lots (larger lots with more green space/natural vegetation)
• reduce landscaping costs (working around the natural areas that are already available on-site)
• reduce pollutant loading to ground water and drinking source water (reduces water treatment process costs)
• reduce long-term life cycle costs   
  
  

Environmental

• provide habitat for local pollinators
• effective stormwater volume management to reduce stream channel erosion
• reduce downstream pollutant loading
• reduce urban heat island effect  
  
  

Aesthetic

• vegetation and flowers add aesthetic value to built landscapes
• education and recreational opportunities
• provide ecosystems that deter mosquito breeding and other pests
  
  

Can LID Techniques be Used in Warren County?
Yes! In 2020, Warren County updated its stormwater regulations and technical design guide to allow for green infrastructure practices for water quality best management such as wetlands, permeable pavements, infiltration practices, and bioretention. Not only is low impact development permissible in the county, but with the numerous benefits, it is strongly encouraged! 

Other examples of Green Infrastructure that can be used as part of a Low Impact Development plan can be found here: https://www.epa.gov/green-infrastructure/what-green-infrastructure

Additional Resources
​www.warrenswcd.com/rain-gardens.html
https://www.epa.gov/nps/urban-runoff-low-impact-development
http://www.wceo.us/

One of the requirements for stormwater pollution prevention plans (SWPPPs) is to include an implementation schedule for major construction operations. This includes things like clearing, grubbing, excavating, grading, utility installation, and other similar activities.
​
The Ohio EPA Rainwater and Land Development manual includes a table of what this general sequence should look like: https://epa.ohio.gov/static/Portals/35/storm/technical_assistance/6-24-09RLDCh8.pdf (pg 13)
​
There are steps that should be taken as early in the construction process as possible to avoid problems with sediment and erosion control later in the project. 

Let’s breakdown those crucial early steps:

• Protect your natural areas. As construction activity is commencing, everyone working on the site should be aware of protected forested areas, streams, and wetlands that should not be disturbed. These should be marked off with easily identifiable fencing. If areas that were meant to be left alone get impacted, it can cause harm to sensitive natural areas and may also be in violation of other state and federal permits.
• Construct an area where equipment and vehicles have a clean exit from the site. A proper construction entrance/exit should consist of ODOT #1/#2's aggregate over a geotextile base. The proper aggregate size helps to ensure there will be enough vibration under the tires to kick mud off equipment and vehicles before leaving the construction site. It is best to have this installed as soon equipment and trucks are moving on and off the site to prevent off-site tracking.
• Install perimeter controls around all areas planned for disturbance. Clearing trees (root ball and all), grubbing, and grading work results in exposed soils. That sediment must be contained on the construction site. Perimeter controls need to be up around the entire perimeter of disturbance to help intercept sediment-laden discharges from moving off-site during rain events.
• Construct temporary basins. Basin construction should be part of the initial phase of construction. Basins must be installed and functional before any upslope development. As soon as the basin is dug, apply temporary seeding treatment to ensure embankments are stabilized throughout construction. Doing this early in the process helps to prevent erosion in the basin and sediment storage problems. The basin outlet structure should also have a skimmer device installed as soon as possible for de-watering off the surface of the basin rather than lower depths of water where more sediment is present.
• Follow construction timeline for remaining controls. Other sediment and erosion controls should also be installed as soon as possible. For example, when streets are installed, a sweeping schedule should be established. As new catch basins or street inlets are installed, get inlet protection on them right away. As lot development begins, make sure individual lot controls are in place. When concrete pouring is in full swing, there should be a designated washout area with controls.
• Communicate with your SWPPP inspector! Keep your inspector in the loop when new phases of the project begin in between inspection periods. If there are changes to the timeline or problems with getting certain controls established, let your inspector know so that they can help provide guidance that can help to keep things on track.  

Monarch Homes and Diggit Excavating met with Warren Co SWCD at a pre-construction meeting with the City of Lebanon where the requirements and sequence of sediment and erosion controls measures were discussed. Since that meeting, the team has been in constant contact with Warren Co SWCD, proving updates on initial groundbreaking and the control installation timelineas well as any changes to controls being used on the construction site.

As soon as clearing and grading work was set to begin, there was a proper construction entrance in place and silt fence around the clearing boundaries that was supplemented with a mulch berm from the on-site clearing. The basin was dug as part of the first phase as well. The basin will be temporarily stabilized and have a skimmer installed on the outlet once installed. 

​We asked our friends at Diggit Excavating for their take on how communication has helped with the development process from their perspective:
​

This is a great example of communication between our agency and developers and contractors on projects and how compliance can begin right out of the gate as a new project begins. This proactive approach helps to avoid many complications later in the construction process. ​

As it can sometimes be difficult to translate technical regulations into feasible solutions in the “real world” on-site, we decided to spotlight some practices with examples we've found while conducting our inspections.

This month we noticed some great Best Management Practices in Hamilton Township on the Valley View Subdivision site. Everyone that enters the site is greeted by a large-format blue sign at the main construction entrance outlining site safety and erosion control rules, so it's easy for everyone to reference at a moment's notice. There is also a great example of a SWPPP storage box containing the SWPPP and keeping it accessible while safe from the elements. Aaron Smith with DR Horton provided some insight into how the stormwater team approaches stormwater runoff on the construction site:

​If you work in land development and construction, you are likely familiar with silt fence. When installed and maintained properly, silt fence is an effective sediment control measure. It is also one of the most common perimeter control measures noted on Stormwater Pollution Prevention Plans in Warren County. However, there is another type of perimeter protection that is becoming increasingly popular and may be a great accessible supplement or even alternative to silt fence: mulch filter berms. Rather than capturing runoff to allow for sediment settling like silt fence, mulch berms filter out sediment as water passes through the berm. 
​

Can I have filter berms listed on my SWPPP? 
Yes! Please do include them on your SWPPP if that is the plan. They are approved and encouraged by our office for use if a project plans to do extensive tree clearing work. Often silt fence is listed by default on the SWPPP and mulch berms are ultimately used during construction due to their benefits. Best practice is to have the perimeter control that is meant to be used written on the plan. However, if things do change as work commences, reach out to your designated SWPPP inspector to make sure the updates are documented on the plan moving forward. 
​

What material can be used?
The Ohio Environmental Protection Agency’s Rainwater and Land Development Manual outlines the specifications for the materials that should be used for these filter berms. The guide specifically states compost used for filter berms shall be weed, pathogen, and insect free and derived from a well-decomposed source of organic matter. This material can include compost, mulch, or wood chippings. For projects that involve extensive tree clearing, we recommend considering mulch berms as a perimeter control practice. For the least amount of land disturbance, your site may even be able to avoid removing the entire root ball of the trees and mulch the stumps for filter berm material. If you have questions about using the material you have on-site for controls, contact the urban team at Warren County Soil and Water Conservation District.

How are filter berms installed?
​Filter berms are installed in the same location that silt fence would be installed: along the contour and away from the toe of a slope. Like silt fence, there are different specifications for spacing based on the percent slope as well. For silt fence, there are very specific installation steps that must be satisfied to ensure proper function. Mulch berms installation is a less labor-intensive process. Rather than trenching, placing, and stretching fencing to be completely taught, berms just need to be built up to achieve the specified measurements (minimum 1’ height and minimum 2’ wide or 2 times the height). 

What kind of maintenance do filter berms require?
The most common filter berm maintenance need is to rebuild the berm to meet the appropriate specifications as needed. Like silt fence, built up sediment should be removed from behind the berm if it reaches over 1/3 the height of the berm. If a berm is completely washed out by a large storm event, the berm material will need to be replaced as well. If wash out continues to occur, additional or alternative controls may be needed, such as a rock check dam, or the size of the berm may need to be modified.
​

​Where can I find additional information?
The Ohio EPA Rainwater and Land Development Manual Chapter 6: Sediment Controls contains a section on filter berms. You can also reach out to Warren Co SWCD's Urban Team to discuss a plan for implementing mulch berms in your current or future projects. 

Rainwater and Land Development Manual:
https://epa.ohio.gov/divisions-and-offices/surface-water/guides-manuals/rainwater-and-land-development
Federal EPA:
https://www.epa.gov/system/files/documents/2021-11/bmp-compost-filter-berms.pdf
Warren County SWCD:
https://www.warrenswcd.com/
​