Erosion and Sediment Control Best Practices
Foreign and welcome or welcome back to those of you who are here last week to today's second of two erosion and sediment control workshops which is being hosted by Kawartha conservation in partnership with City of Kawartha Lakes and the Sustainable Technologies Evaluation program also known as Steph my name is Sarah finnemore and I will be assisting with today's course on behalf of step and today's course will be instructed by Lisa Rocha from the Toronto and region conservation Authority and she is a long-standing project manager with Steph so before we get started I would just like to mention that while audio is available we ask that you save your questions until the question period or type your question in the chat at any point during the workshop and I will either read your question out or call on you to turn on your mic during The Question period today's session is being recorded and I will now pass it over to Lisa thank you Sarah oh hi everyone welcome to for joining to welcome and thank you for joining us um for this Workshop today as Sarah mentioned I'm Lisa Rosa I'm a project manager with the sustainable Technologies evaluation program at trca uh over the course of my time at trca my work has been focused largely on stormwater and erosion sediment control research and guideline development and most recently I led the development of the updated erosion and sediment control guide for urban construction which we released in 2019 conservation reach out to me to organize this Workshop as they really are interested in raising the bar on erosion sediment control in the region and definitely feel that Education and Training is an important integral part of that goal so during today's Workshop I'm going to be focusing today on providing the latest guidance on ese best practices and it's going to be drawing largely from information in the 2019 erosion sediment control guide as well as some curriculum from other ese courses that Steph has offered over the years I don't want to talk too much about this because I think a lot of people here are attended also last week but um the program I'm with at trca is the sustainable Technologies evaluation program it's a conservation authority-led right now the members are like some go region conservation Credit Valley and trca and we are really focused on just supporting broader broader implementation of sustainable water Technologies through research monitoring um and evaluating those Technologies then we look at strategies to overcome any potential implementation barriers like whether it be cost or a lack of understanding of how they work will tackle those strategies those kind of barriers by either doing research or advocacy or training we also developing tools we have a treatment train tool for low impact development we also have like online tools like the wiki which is a Wiki resource online guide for low impact development all aspects of low impact development design and maintenance everything you can need to know about low impact development and we also develop guidelines and policies to support broader uptake and things like today one of the primary things we do is education training knowledge transfer so events like today is one of the primary focuses of the program and mobilizing the knowledge that we have gained through our research okay so today I'm going to be covering um these key topics um maybe focusing more on application of erosion sediment controls and specific topics like uh dewatering protocols and winter preparedness we'll also be discussing legislation that's relevant and uh you need to know if you're involved in erosion sediment control or construction you know at all really when designing ESC plans for construction projects we're also um if you're interested in in more detail on the ese fundamentals like an overview of the es erosion methods and sediment control methods and best practices I also encourage you to check out the workshop that took place last week um I know kortha CA will be posting it online soon so I can keep you posted on that and and send out a notification when it is posted but there's a full video so if you need any of that background information that you didn't attend that session I would encourage you to try that one as well I will be stopping for questions and maybe a five minute break at one point so feel free to put your questions at any time in the chat and I can address them when they come up when we get to the discussion period okay so just a um again I mentioned the ESC guide in my intro but I wanted to just focus um just kind of give an overview of what it is so it's to me new but still really new-ish uh all because it's 2019 so it is has been several years since it came out now but um it's a significant update to the 2006 guide that was uh the greater Golden Horseshoe area conservation authorities erosion sediment control guide at the time many uh conservation authorities municipalities did uh adopt those practices this is a significant update and some of the main things I think are new and and interesting about this one is the qualitative erosion risk assessment methodology so it's a way of looking not just at your soil types but like asking people to look at different things that affect your erosion potential and do a qualitative assessment to understand where those risk areas are and how you can best take advantage of and invest your money in your bmps like and putting them in their right location and reinforcing the highest risk areas we also tried to clarify the AC approvals process with flow charts and checklists we heard a lot of the time that proponents and Consultants putting in applications were sometimes confused by processes approval process so we tried to make that a little bit more clear we updated information on best management practices so that we would no longer use the proprietary names um like you know filtrex silt docs with an X everything's generic uh so um there's no um you know need to keep updating every time there's a new product on the market um it's just like a general product category that is used to name everything we also have more guidance for end water isolation VMP we did we included a sizing calculation for in-water isolation barriers which is interesting like a very simple calculation based on the amount of risk you're willing to tolerate and how long the Coffer down for example is going to be in place so that's a really interesting one that we included this time around we also included description of risks to low impact development features like bioretens whales infiltration trenches and Chambers all these infiltration based on the ground green technologies that are becoming more and more common can be very clogged and compacted during the construction process if they're not protected and so we included some pretty detailed guidance on how to protect those we also include guidance on ESC Effectiveness monitoring tribility Target for the first time we always have heard from the industry like we nobody understands what really the goal is like what should my water quality what should my turbidity be Downstream like what was the maximum tolerable increase from my site and there's not a lot of concrete data out there not concrete data concrete guidance policy rules out there that very clearly states what those should be and so they included some guidance that we think is make sense and if you wanted to look at the guide in more detail and just peruse it yourself and keep it it's um available at sustainabletechnologies.ta slash ESC Dash guide okay so getting right in we're going to dive into some information on pumping and dewatering best practices for construction projects I think the important thing is just having dewatering protocols and plans in place will allow you to deal with your plan dewatering and any unforeseen dewatering activities that have to be conducted so that you can just you know always have a plan to mitigate sediment releases during those activities the ESC plan should definitely include dewatering protocols that direct staff on how to handle active and passive pumping discharges some of the common activities where you can anticipate you're going to end up needing pumping or dewatering would be sediment control upon dewatering to clean it out facilitate any like re-grading or maintenance dredging of your sediment control ponds like on a a multi-year construction project you should definitely have to clean out your sediment control ponds at some point it's not going to be okay to leave the sediment control Pond without being cleaned for four years or whatever pumping out storm water that accumulates in an excavated or low-lying areas following a large event so that you can continue your work after I'm using a sump pump to remove groundwater and excavations that extendable the water table and repairing or replacing any underground services so some of those are the most common activities we're going to need to do this work um there's a lot of important considerations really to think about when you're trying to decide on your protocol and make your plan one of the things you want to think about is your allowable water movement rates that are specified in your permits so um for example in a permit you take water or EAS are environmental activity and sex or registry either registration you could be required when you're taking they might those might be required when taking more than 50 000 liters of water in a day from a surface or groundwater system but pumped water is being discharged to a municipal sewer for example discharge permits are also typically required and while specific permits are going to vary like you're not going to have the same requirements for municipality to municipality they do typically include like a maximum allowable discharge rate also you want to consider the receiving water system and the standards of that system so water that's discharged directly into a municipal sewer for example either a storm or sanitary is usually subject to the municipalities a lot of them local locally would be the sewer use bylaw here I'm in the GTA um and there's the sewer use bylaw specifies specific contaminant limits some of them are actually quite strict so when you're dewatering you have to abide by those limits so that's what you have to understand before you're going to be pumping water whether you're meeting those criteria for the discharge to the Sewer um then if you are actually discharging directly to a natural water feature my recommendation would be to consult with the turbidity targets that have been provided in chapter 10 of the erosion sediment control guide those would be the ones that would be the most applicable um and you know advisable to adhere to there's also temperature standards to consider for discharge natural features when you release water natural features they should fall within the appropriate temperature range that's based on the organisms supported by that habitat so for example groundwater can actually be significantly cooler than the receiving water system so you might want to make sure you allow for bringing a gradual initial release um to allow aquatic organisms to adapt to the temperature differential also where you're discharging much warmer water I'm in a cool water fishery or cold water fishery you want to ensure that you're not exceeding the threshold which with mnrf typically recommends for example for cold water endangered species like the red side days and um which is found in gtha areas the upper reaches you don't want to be exceeding 24 degrees Celsius um also you want to look at how close you are to groundwater if you're doing groundwater dewatering how close you are to Natural surface features when groundwater is being dewatered near a surface water feature the water level in the future could be impacted by that dewatering and so depending on the zone and influence and the amount of water that's being pumped out you have to consider those factors it's important to know the groundwater condition in the area in advance of doing your dewatering plan so if a natural surface water feature is located within the anticipated zone of influence the local conservation Authority should be consulted to provide advice and help establish strategies that you can use to prevent impacts to the hydrology of that surface water feature when you're looking at also erodability at discharge locations you want to make sure you're preventing erosion at the outlet of a dewatering system because that's just as important as ensuring you you treated the water in the system because what's the point of treating water and dewatering treatment system if you're just going to mobilize sediment again along the flow path between the discharge point and the receiver so what you want to do is make sure it's stabilized with stone geotextile vegetation roll erosion control products or whatever is appropriate for the flow rates and area in question and you want to you know you want to consider what those flow rates might be and whether the ground is going to be capable stable enough to to support those flows in that area and always consider flow dispersion and energy dissipation um and yeah especially if you have a concentrated or high flow rates that are coming out there you want to consider whether you can disperse those flows and make the erosivity less um you also want to consider whether there's any requirements for Quality under quantity monitoring so for example permits issued for dewatering activities permacy take water conservation Authority permits Ministry of environment permits or authorizations Under The Endangered Species Act all even sewer discharge permits they include requirements for periodic or continuous monitoring of the quality and amount of water that's being moved so you have to consider do you have to you know do monitoring of this and how am I going to monitor this discharge and with my monitoring plan I'm going to be for this and lastly really important is contingency planning an effective contingency plan can be implemented like on short notice so it means that materials are available or a vendor that you need to hire quickly is available and accessible so like for example a really proactive approach would be a potential to have if you have a potential water quality issue is to have a plan to get a dewatering tank like a wee or fractionation tank or active treatment system on site and installed quickly if needed so having that information on hand having materials on hand to replace when something's wrong all these are really important part of your contingency plan because it's pretty odd A lot of times something will go wrong that's on construction projects it's pretty common and just having the contingency in place demonstrates your due diligence and mitigating sediment releases um so some of the most common like and this goes from like pretty basic to like pretty complicated and expensive um best practices for pumping and dewatering so just pumping water out and treating the water before it's released and also dispersing it one of the main things you see a lot of times are sediment Bank geotextile fabric bag that's the one in the top picture there it provides energy energy dissipation and filtration so what happens is you're kind of like blowing water down by going through the bag and sediment will fall out there's some filtration effect but in general it's actually the fact that you're just slowing the water down you're also dispersing the flow over like a much larger area not having like a concentrated pump um Outlet anymore so that's really beneficial there another option that's the middle picture you can incorporate polymer flocculants they cause particles in the sediment to bind to one another so they become larger and heavier and more likely to settle out or be filtered out of suspension so you can incorporate them in something like a ditch configuration which is pretty popular because it's like passive passive meaning once you've discharge it from your your pump hose it just flows through the Stitch into its eventual destination um and so that's one common way to apply polymers if you want to speed up how quickly water is going to be clarified another way is just another level of kind of expense this would definitely be because a lot of times you have to bring in a vendor to do this A supplier would be dewatering Weir fractionation tanks coming in various sizes they can be pretty easily shoehorned in like you know maybe there's a project where you want some detention but you didn't build a pond or don't have space for that these are you know commonly used where there's not a big footprint it provides just an opportunity for settling the Weirs help dissipate the energy and you can optimize the sizing of the the wear tank based on your targets and your particle size distribution of sediment and like what pump rate you need to really achieve on your site so manufacture not manufacturer but supplier of those products that are going to bring those services to you would help you do all that and then lastly um that's the bottom picture on the right there is active treatment system that's more like what they were talking about in the video um and that's when you want to do more intensive water treatment depending on how many different components you have in a system like that it's like putting a water treatment facility on your on your site really it's suitable where there's less intensive less intensive options are providing insufficient treatment and you have very specific contaminants of concern and very you know strict discharge requirements that you can't otherwise meet it may be the only option you have in those cases and so um they they are used they exist they're out there and there's a lot of projects where they may be needed so something to consider it usually includes something like a polymer phase or something like that like a flocculent type of thing and then they may have polishing a polishing container so you would pass through something like a sand filter um I mean I think you can get as many bells and whistles as you want to make the water as clear as possible at the end of the system but yeah uh there's different as you can see there's different um containers that house different parts of the treatment treatment train and like as you can see down below and then you can even check the water at some of these at the end and just kind of see it pouring out and see how clean it isn't and test it even so that's something that's available going into a little bit more about sediment dewatering bags these are composed of geotextile material they remove sediment suspended from terrific constructions like discharges It's always important to put on a flat stabilized area grass if you can but you know grass that stable grass not brand new grass and stone lined is also a good option I've seen some examples where it would still have to be a stable surface underneath but sometimes we'll put like a pallet of some wood pallet just to make it easier to lift off after and just give it ability to like drain below so it's not sitting flat on the ground at least 30 meters away from the receiving water system it's always better in a treatment train approach sorry do water and treatment train approach so that's where you would include more like barriers around it and ideally a concealed sock barrier around it and just provide like multi-levels of treatment around the bag so that you are getting the maximum amount of treatment um the water would be pumped into the center into the bag and then blow out around the bag to all all around the perimeter of it to like a silt sock and then beyond so you always want to make sure it's securely clamped to the inlet hose and is inspected regularly replaced when full so that's really important inspecting those is important because um if that goes wrong and it can't go wrong then it's a big problem and a lot of sediment releases can happen that way okay so this is um these this Duty watering treatment train I was trying to describe earlier you're waiting I'm going to try to look at this a little bit Yeah so let's better closer look for me so um just this is just to illustrate that you can apply something like this in normal and Frozen conditions um so if you want to use in a normal condition you can use the the sediment bag anti-watering bag in the center you want to Overlay the area with Filter Fabric so as you can see there's Filter Fabric underneath the geotextile bag but over top of the staked in filters filter socks and see you could see there that they've placed it on a wood pallet skid just to make it easier for water to drain and also for it to be taken away after and this just provides like they also secure the geotextile fabric with these sandbags and just gives you like a multi-level it's really the multi-barrier approach but you're just enhancing the treatment as much as you can with measures that are relatively simple to put on site if you do not if you have Frozen conditions you can just pump the water directly into the center of this area instead of having it into a bag and then just oops put a second layer put a second layer not layer but perimeter of silt socks to enhance the amount of treatment and settling you're going to get from the water that's being pumped in there so that's a winter option which sometimes there's not a lot of winter options so you always want to take advantage of the ones you have okay speaking of winter options um we're going to talk a little bit now just about winter preparedness which I know is a topic that can be really challenging um so when you talk about construction sites during the winter um there's really not a high potential for erosion when it's frozen but when there's an intense there's a thought event and then an intense rainfall um and when you have those unstable ground conditions caused by snow melt or melting Frost that's when you have the highest potential for erosion spring after this when after when there's a thaw and after a lot of that snow melts is when you see the highest incidences of sediment releases and and Spills and things like that from construction projects so um when you have mild winter temperatures and rains because the ground's not stable and the challenges there's many challenges with installing sediment and erosion controls when you're trying to put them in in the winter so that just exacerbates the problem um and so there needs to be kind of a different approach to Solutions so here kind of just illustrates what happens with the soil and so the Frozen grounds generally erosion resistant of course but when but the soils that have high moisture content are subject to heaving and freezing action and they're easily eroded upon dying so um alternating when you alternate the freezing and thawing cycle it creates pressure which lifts the soil up out of the ground and then the downward pressure damages the soil by compacting it while the upward pressure creates that Frost heave and damages the soil structure breaks down soil bonds and it makes reduces aeration it just creates poor drainage condition in the soil um and so that Frost tube cycle occurs mostly in early spring sometimes late fall and it's when you'll have like cold temperatures and abundant soil moisture are present and that's when you can see that kind of start to happen the frost heave and heaves can happen in any type of soil but soils that retain a lot of moisture like silt loam clay are their most the most prone to heaving really so I mean this is the problem here I mean we're kind of focusing on the problem and we're going to start talking about Solutions but um your ESC toolbox is diminished in the winter because of the conditions that you're faced with so when you're talking about implementing something for like during the winter season when ground's frozen um these are some of the challenges with vegetative ground cover you can't establish it outside of the growing season and it's automatically the most effective Version Control is not available hydroseeding is challenging because stabilizers are not as effective in cold conditions and you're going to have poor growth over the winter when you're talking about diversion structures like cut off swales it's not as easy to try to build anything like that when the ground that is frozen also sediment basins are hard to install in frozen ground and they can also be overwhelmed by Spring melt even if you have one in place already so you can't just rely solely on that as your only BMP and not expect that it may be overwhelmed by the Spring Mount flows that you're going to experience um still fenced again because it's trenched in it's hard to install and can't install really in frozen ground and um it can often fail during spring melt if it's not reinforced well or not bolstered well and not maybe had multiple berries in place with erosion blankets um you can't really install it that well on frozen ground and improper installations that are not eaten will slip away in those melt flows with grassline swales again insula insulation on like a frozen ground is difficult and then even for Paving um I think Paving can be possible in cold conditions but it's not as easy it's challenging so a lot of these things are not as readily available like some of the tools that you would use to stabilize your site and and prevent sediment mobilization and so if you think about it like how do you prepare for winter and like I think in the case of the fact that there is less in your toolbox what it means is you can't respond in the moment as much and just address things there you have to be way more proactive and think before winter and make plans before winter so you have to before you know anything you have to do a pre-winter inspection and assess you know the current site conditions and ESC practices and you have to determine if any maintenance is required and what you're going to have to put in place to bolster existing ones so you're going to be ready for any kind of melt events and all that so you want to ensure your basins and traps have adequate storage capacity you don't want to go in to the winter season having sediment Basin that's full of sediment you should be they should all be cleaned out long-term stabilization should be established anywhere you can so on exposed slopes or stockpiles and buy methods that are appropriate for that slope steepness and length examples like soil cover tracking rolled erosion control products or even sod you want to inspect the erosion controls to ensure they're securely installed and in good in good working order you don't want to have them just not functioning at that point in time you want to remove storm Inlet sediment controls at locations that can cause safety concerns so you may have like ponded water and ice you want to replace those prior to snow and increase inspection to ensure those flows are not being impeded there from that control you want to stabilize the bottoms and the side slopes of ditches and diversion channels and just look over your site anticipate areas of potential runoff like where are you going to have a lot of runoff inflows from Spring Mount or any major in the middle of the winter melts and determine if you need more escs than if you need multiple barriers in place so when you want to stock your go back and start stocking your toolbox again and rethinking about okay like I can't do that but what can I do that's the key thing you want to start by preparing detailed site winterization plan so you want to look at what strategies will work for you and you prepare a site winterization plan that's going to be implemented during winter construction works and in the plan you want to give a special consideration to how each control or practice will be maintained so that's going to have to happen throughout the winter it's not just like you go and leave it if you're not doing active construction and remembering your best defense is always on multiple lines of defense or also the mods also known as a multi-barrier approach where you have multiple controls in sequence and if one fails there's always a backup so you have that redundancy in place um so when you consider stalking your ESC toolbox all ESC measures that can be installed should be installed um and so still fences and other practices requiring Earth disturbance must be installed prior to Frozen Ground um there you want to maintain adequate buffer width from Perimeter controls and large access points have a snow management plan that shows snow pile locations Downstream of exposed soil areas and notes that EST measures should be cleared in in prep for your inspections and maintenance and drainage structures should be kept free of snow and ice dam so a lot of things to consider when you're just restocking then when you consider there's a few more options so you want to also limit the exposed area to those that can be in which works gonna occur within 15 days and or that and that can be mulched in one day prior to any snow event so multiplied and consider that multiplied for um stabilization should be applied at Double the standard rate when you're talking about applying it in the winter if you delay if if a delay is anticipated in finishing slopes and all the exposed errors should be covered in mulch like a rolled erosion control product like a blanket and then combinations of these depending on slope length and gradient you could also break up the slope by using like flow interrupter like cell talks cell phones choir logs along the slope to just interrupt the flow and and take that away some of that erosivity and also consider slope drains again multiple lines of Defense are always the best way to go in this case if the slopes are finished then you can cover them with an erosion control blanket that can be seated through the spring assuming that you cannot establish permanent stabilization at that time but the best ESC measure known and available is spinal stabilization or permanent stabilization you also want to consider choosing more effective winter specific erosion controls but not like the typical measures that we always see talked about so for example you might want to do something like a mulch Burma map parameter rather than a silt fence because the berm can be constructed on top of frozen ground without compromising its Effectiveness whereas you can install the silt fence in frozen ground or if you do do a winter installation of cell fence it's not as resilient as trenched insulin uh so we want to also ensure all exposed subgrades get graveled or tracked to create like a rough surface that helps slow all your flow velocities and lastly you just want to make sure you regularly schedule winter ESC inspections um regularly schedule them and not like necessarily less than you would in the other season if you are continuing work during the winter um this is just a little example it's that's from Maine and it's a winterization plan so this is something that would be included in your ESC plan all these kinds of notes the dates are going to vary from place to place based on like the growing seasons and and all that but it's very specific and detailed and um it's specifically just focused on stabilization before winter and provides dates um very specifically directing people working on the site as to when they should be achieving these specific stabilization milestones and so I think something like this would be really important as part of your winterization plan to include with your ESC plan okay so we're going to move on to inspections and monitoring I feel like we've had quite a bit of time so I'm just going to ask now Sarah if you have any questions that have come up in the chat I think I would probably see them but if anybody has any questions they also can you know just say them out loud I will have another like spot for questions soon but I just wanted to give a chance now after we've covered all that content I have no questions in the chat yet um if anyone has any questions just yeah put them in the chat or raise your hand we can get to get to them at any point so I think for now we can keep going sounds good Okay so the next few slides we're going to consider um the best practices for inspections and monitoring so you can have a great ESC plan but unless you inspect your site and do some sort of monitoring of the effectiveness of Eurovision sediment controls and of course after you've done that work of identifying those things maintain your controls based on the outcomes of what your inspection and monitoring has discovered the EOC plan could be the best thing in the world but it won't matter because you're not following up as like as to what's really happening day in and day out on your site so it's crucial crucial to having a say that is effective um the inspection is just like your walkthrough of the site Carry Out by Adelia qualified person to qualify to do inspections and we'll talk about what that is um for monitoring you want to just on an ongoing or periodic basis assess like the quality of your site discharge and other monitoring parameters depending on your site you may have to look at temperature you may have to look at certain contaminants just TSS you may have to look at flows but you want to consider doing some sort of monitoring Me Maybe pretty basic or or very involved if it's required of you but um monitoring is important because it's really the point where you see okay erosion sentiment control doesn't look like it's working the cell fence is down it's not looking good you don't really know like what that translates into at your site discharge points in terms of an impact um an impairment of that water quality unless you do some sort of monitoring um so something to consider and maintenance is just mostly a lot of sediment removal repairing esc's adding upgrading replacing as needed to make sure that continues to be the level of protection you designed for ASC inspections the goal is to regularly assess the effectiveness of individual escs and your overall ESC plan you want to also in your inspection identify the need for maintenance so example sediment removal and repairs you want to identify areas where ESC should be replaced or augmented due to the fact that you see repeated failures um I think also like one thing you'll see on inspection reports and one thing I've seen that's been really good in the past is um you know just how many weeks this has not been functioning properly so like you know it's been three weeks this still hasn't been fixed identifying that you've you've said this before this is the third week I'm identifying this problem that's something important to track pictures locations of where these impaired areas are are all important to including your inspection report um and Beyond the condition and functionality of the controls you want to um in an event in an effective inspection um you want to do ongoing assessment of the adjacent natural features and you want to actually look and see like if you're having an impact in what the feature looks like and kind of track over time whether it looks like you're having some sort of negative impact on the feature and so not just stopping at your site perimeter but where your discharge points are into other private properties or receiving area receiving natural spaces you want to look at those areas too and track that and as part of your inspection so inspection is only half the story so the effectiveness of the construction site inspection is depend dependent on the frequency and immediacy and robustness of the actions that are going to be taken to address those deficiencies so you can do inspections every single day and just identify everything perfectly and if something's not done proact like quickly to address that and and like really take that seriously on the site Personnel the contractors are not uh taking that seriously and and mobilizing efforts to fix those things because they just see it as a formality just inspecting for the sake of inspecting then it's meaningless to have an inspection it's important that it be carried out by a qualified ESC inspector someone like cysic so certified inspector of sediment and erosion control another designation in the Canadian standards Association inspection and maintenance guide uh it's actually modern guides sorry I remember the name exactly of that standard but it came out around 2019 as well they identify um skills and not like knowledge and education for somebody that would be considered a qualified erosion and sediment control inspector q-e-s-c-i and it's not it's not dissimilar to seismic it might be slightly more onerous and there's also q-e-s-c-i-it in training that they um acknowledge as well and just remember the ESD plan should evolve as necessary to ensure that the features are protected so the efficacy of the inspection program is contingent on like applying the information collected during inspections adapting the AC plan to study conditions and making the repairs and maintenance doing the maintenance that's identified as being needed in those inspections so how often should you inspect the site you want to do a pre-construction inspection to verify the original setting controls are installed based on the approved plan and then once construction Begins the inspection should occur on a weekly basis during active construction you want to do it before and after significant rainfall events um you want to do it after significant snowmelt events after any extreme weather like for example like a windstorm that could have damaged some of your controls like particularly silt fence you want to do it daily during an extended rainy or snow melt period and monthly if the site's inactive so if it's greater than 30 days you just go on a monthly basis um if none of those other conditions are present if there's a spill event you want to go during or immediately following that occasionally during an event if it becomes necessary to see how water is moving through your site that's a very smart thing to do if you have the capacity and you know the budget to do that just to visit the site during an event just to see how water is moving and not just the aftermath where you see something's been damaged but I don't know how this happened and where the water flowed to get here and how how it all happened so during an event if it's safe to do so and within budget and possible you want to inspect before winter shutdown to ensure the site is ready for freezing conditions and thaws and at the end of construction to confirm that you've achieved at least 80 percent effective stabilization on your site so um for BSC performance monitoring this is the monitoring of site discharges and or Downstream water quality which can help you understand whether the controls are working to actually mitigate environmental impact turbidity is a parameter that's often measured on construction sites to assess ese Effectiveness and it's used to serve as a proxy for total suspended solids so turbidity is an optical property it's the cloudiness of the water so it's not exactly like just sediment it can be cloudy for other reasons but in practice the water turbidity is often measured and used as a proxy for TSS which is the total amount of actual suspended solids since the turbidity can be measured on site in real time with something handheld or like a station that's permanently in place in like something like a YSI meter and for this reason because duration of exposure to elevated turbidity is also an important factor um when you consider like whether that's going to have a negative impact on ecosystems you want to be able to address and get a number right on site and so they're receiving water and effluent targets that we put in the erosion sediment control guide are turbidity targets for that reason because you can't measure TSS on site and so you can't get that kind of um as easily duration of exposure and on-site real time um kind of information through that process you have to send it to a lab and you're going to have monitoring your monitoring approaches are definitely going to vary based on your site details where you can monitor what the project needs are based on what you're actually doing what kind of contaminants could be present what are your regulatory requirements sensitive areas nearby there's so many things to consider so here are some of the site specific considerations you want to look at erosion risk and where you have like a high potential for erosion you want to do more intensive monitoring for high risk erosion sites when you look at your receiving water system for example are you going to a natural feature or the sewer system and what are the thresholds that you're required to meet in either those instances also is the low water level deep enough to even keep a turbidimeter submerged if you had like an online station so that's something you may not be able to do if you don't have enough water is the receiver accessible even is it too far from the construction site is it going to be physically possible and safe for you to do that what is those is there a presence of any species at risk or protected species that are Downstream of your site is are you subject to any of those kind of approvals permissions regulatory requirements that are tied to those types of species you might need more intensive continuous monitoring on-site straining to species at risk habitat and it's really usually determined by the regulatory body administering the legislation you also want to consider the type and location of discharge points so is it easy to get to the equipment to install and to download and you have to look at safety considerations also cost consideration so if you if you were to monitor Pond duffel and if you chose that that was the way you wanted to go like I'm going to look at affluent from my sediment control ponds because a lot of my flows are going through ponds that's just how my site is set up how many pawns do you have um is it going to be expensive how are you going to set that up at all these different ponds or do you just have one Pond and that's not too big of an investment so a lot of considerations when you're when you're putting together your monitoring approach and it's very site-specific for sure okay um I did see a few questions so before I get into this kind of um part of the um presentation that's kind of just going through some like examples of problematic um if things that happen on erosion inside on construction sites uh ESC failures I'd like to maybe answer the two questions I think that came in yes uh so the first is actually not technically a question but if there are species at risk inspections may need to be conducted daily during Wildlife active Seasons if it's required by mnrf or macp and so the second are you going to be speaking about the fines and penalties that you know of that are being applied to situations where ESC plans have failed or have not been followed um there there is some more information I'm not specifically speaking about fines and penalties in a specific way like this is exactly the total Max um amount that um can be levied for each uh like um violation under those different acts I think I put that stuff in the ESC guide where it specifically tells you like I think the maximum penalties may be um that can be levied for different violations um and I don't necessarily have a lot of information that I have specifically even though I've spoken to like our enforcement here and there it would be local to where we are in terms of um I only have like one example in my mind where there was a really significant fine levied and I don't even know it was in the media so if you wanted to look into this but it was specifically related to like a solar farm and repeated instances of exceedances like really poor erosion control um and they were fined heavily and if you if you guys want I can kind of find that example and send it out after but the details are kind of escaping me right now but that was one of the most recent oh solar farm in Hamilton Township okay so thank you I think that was Gary Gary yes thanks for letting us know yeah so there is that's in the media that's one of the big stories I've heard but other than that a lot of things are I mean locally there's job work orders sometimes um and then you know there can be penalties where it's more just like you have to rehabilitate this and it's expensive um but in terms of specific fines in our area um I would have to ask our I could ask our enforcement officer if there's been something recently but not I don't think necessarily it's as common as it may have been and I want to say like back when I think DFO maybe had more um kind of enforcement and control over these things where there was more oversight in maybe a few decades back even where it was a little bit more serious where there was like kind of that serious tone taken at least in our jurisdiction to those types of exceedances and fines levied but it's just been I think progressively less over the past few decades so at least where we are but I would love to hear from anybody else's experiences because I know we're all coming from different parts of the province so okay maybe we'll revisit again when we have another question period um is there anything else there or can I can I continue I think we can move on to the next section okay good okay The Good the Bad and the Ugly so I'm just gonna show a bunch of examples here hopefully this will be a bit interactive and not so um just much me just talking and taking up all the air um so it's just an example there's a lot of things that went wrong oh sorry Gary um can you read that out Sarah it's harder for me to see that uh so from an macp perspective if the ANC is required through a provincial officer's order the essay is not created and or followed macp May pursue charges non-compliance with an order as an offense under the EPA mm-hmm yeah I think I think all these there's all these potential for offenses I think it's I guess the the message the general message I have it could be wrong but I'm pretty sure this is what it's like in our jurisdiction is that it just doesn't happen very much um and even though the mechanisms are possible the enforcement is just not really happening um and so somebody could be fined for something but isn't a lot of the times and there's no enforcement there's not enough Enforcement Officers or there aren't regular inspections from by enforcement um that would identify those things that's what I've noticed but I can confirm with enforcement like how things are happening lately and whether that's changed but in past conversations with them that's kind of been the tone um so if anybody wants to chime in I mean you can type it in the chat and maybe Sarah could read it off but I wanted to kind of show this as an example this is a site where the site we worked on was supposed to be like a really good demonstration of a whole bunch of erosion and sediment control practices Beyond just the basic um still fence and a pond and so they were supposed to be like kind of a higher level standard above and it's clear they did spend a lot of money trying to put in erosion and sediment controls but then weren't always executed very well and so this is an example and particularly anybody who attended the last Workshop where we talked about the proper installation of things like this I'd love to hear if anybody has any thing to kind of like comment about what exactly went wrong and why there's um they've seated they've they've seeded this see does come in a bit and they've also um used an enrolled erosion control product but they still have a gully there okay I'll go ahead maybe you guys will chime in on other ones so always considering there's there's actually a lot of things wrong and not just the the thing that's mentioned here so it is not it does seem to be the wrong orientation so it should um it should be installed down the slope and extend to the top of the slope there should be an anchor trench at the top where it's keyed in there and at the bottom and be in continuous contact with the soil surface and there should be an overlap on those edges but it also seems like this slope could have been could have benefited from maybe a slope drain it doesn't seem like the seed that was there was established enough to receive the flows that were going down the slope and so there's a few things that could have been maybe improved and the unfortunate thing is it it's an invest investment has been made here and money has been spent but at the end it's still like not working very well so it's kind of wasted effort to some extent so yeah proper installation is really important in that case I think another example of a ruled erosion control product installed for like a cutoff swill in this case like well what went wrong here again it's the installation and orientation of the length to some extent so the strip should be applied parallel to the direction of flow and as you can see it looks like almost like either this is torn or the seam was in the middle but it should be anchored at the top of the slope on both sides and being continuous contact with sole surface and overlap again could have maybe benefit benefited from some more um Stitch checks or something to slow down flows if this is too much but it does seem like there's rip and and in the middle there and so it could have just been the way the blanket was installed that wasn't ideal in terms of orientation I also want to consider when you're installing that clods in the soil will create air pockets which is where stormwater goes through the blanket and erodes this all below and that's exactly what you don't want you don't want really good ground contact you don't want these kind of um unprepared soil where there's these clods and create a tenting effect that's really bad for blankets here's kind of an example of unprepared soil and how it just won't work and water will be flowing underneath there also on so on the left you'll see the tent there's tenting it's not really properly prepped the slope it doesn't appear to be properly anchored to the slope with staples um and on the right you'll see like really good ground contact UM good soil prep and ground contact is ideal there and that's kind of what you want to be seeing when you're installing a product if you want it to work because if you've spent all that money to purchase it you want to make sure you take it all the way and install the property as well here's an example we talked a lot I think when I do the best management practices content which I did um last week on Thursday time to talk a lot about slope drain so here's another example so why is this slow promoting it does seem like they did try to install a slope drain I had some people in some classes say well maybe it's not actually installed properly because of the way it looks but assuming it is installed properly why is it still eroding um does anybody want to chime in or provide the answers I mean in this case it does seem like they've mulched the slope um but it doesn't seem like it was sufficient um protection stabilization heavy precipitation directly on the surface yeah that's right right thank you uh can you read some of the other oh the single drain Maybe Can't convey enough flow I would say that's true too it's unclear what's happening with the drain it does seem like there's maybe some sort of berm ditch situation halfway not halfway but at the first quarter of the Hill there that's supposed to be collecting flows but water incident on there is clearly um still causing that real erosion and it doesn't seem like that mulch was enough to protect that surface based on the flows that they're getting so I think um there needed to be some better stabilization or maybe the slope drain needed to be a little bit improved or maybe they needed to install like another interrupter flow interrupter and then convey from that point too so that you just don't have such a long slope and that's where water kind of picks up speed and becomes highly erosive and then you start to see the rails forming like almost towards the end of the slope there um here's another situation where maybe a slope train could have helped to mitigate this problem and this failure so again it looks like it's been mulched and then you see that there's definitely a point where concentrated flows are just even just roughing up the surface yeah roughing up the surface before you mulched it would make a difference too and just create like more um kind of slope it slows will slow down if it creates a roughening and here you see yeah slope drain could have had a good a maybe effect on this particular project where there was definitely concentrated flows flowing down there and if they had just kind of contained it to that area and then directed it down a slope drain and that would have been a stable thing to take down the hill down the slope instead of just flowing over your stabilized surface and just washing all that mulch away here's another example yes there's a silt fence sediment fence but there are no posts and you should always remember there should be no more than two meters apart structural fencing support like page wire or 10 by 10 wooden posts would make first stronger sediment fence so I mean that's a lot of water it definitely needed to be stronger but it doesn't even meet the minimum criteria where they're two meters apart so I mean there's a lot of problems on this particular one but there's an obvious one and then always consider like if you do expect it to be potentially um overcome you can always bolster with options there are options to make it stronger with this sediment fence installation I'm curious if anybody's aware of why why it's not quite right there let me know if there's any answers I can't always see them in time no J hook yeah thank you Amber doesn't stop not terminated properly yeah we need a j-hook you always want to terminate you want it to go up the end runs of any perimeter control should extend distance up uh option to prevent flow from going around not wide enough could J hook likely not sorry can you read them Sarah they disappear after a while for me uh so not wide enough could j-hook likely not the proper control yeah but whenever you don't J hook it's easily for water to flank around the measure so that's something to always keep in mind it's the same thing with any ways to handle staking when Bedrock close to our ad surface um can you read that audience sorry it disappeared again are there any ways to handle staking when Bedrock is close to or at the surface so it's taking for a sediment control fence I guess I believe so yeah if you can't get the stakes into the into the ground um that's challenging so you definitely I mean consider a perimeter control that doesn't have to be staked in as far so there's still talks which people do like um put a bit of a depression and then they do get staked in but maybe it doesn't require as much you could consider the same things you would consider in Frozen conditions so some of the stuff we talked about in winter but again like the winter like frozen ground installation of silt fence is not going to be as effective so that winter installation would be that you put like a sediment silt still talk on the Upstream side instead of trenching it in to keep it in place but you would still need to stake that in too so you'd have to get like some sort of Leverage in there but anything that can't be any of the perimeter controls you're going to consider so the other option in the winter one was just like a mulch firm um but anything you're going to have to consider something that creates a burn but doesn't like allow water to pass underneath which is what's going to happen when you have um something that's not trenched so there are some perimeter controls considered but like if it's not going to be trenched in if it's not possible to like stake or transition in very much it's just going to have to be more regularly maintained and then another another way to look at that will means I have to have multiple barriers or be more careful in that area because I can't make something as strong as it would otherwise be that would be what I would t
2023-03-12 20:49
