EVERYTHING DRAINAGE WORKSHOP

Transcription

1 Present The EVERYTHING DRAINAGE WORKSHOP Introduction: Why are we here? There are three main types of sewers within the City of Kingston: Sanitary Sewers which transport wastewater that we release from a drain, toilet, sink or appliance. This flows to treatment plants where it is cleaned before being released into Lake Ontario or the Cataraqui River. Storm Sewers capture rainwater and snowmelt from residential and commercial properties. This water flows into nearby watercourses, streams, rivers, or wetlands, into the Lake Ontario. Combined Sewers In some of the city's older areas, there are some remaining combined sewers. In a combined sewer a single pipe carries both sanitary and storm drainage. During dry weather, combined sewers carry all contents to treatment plants. However, during heavy rain or snow melt there are occasions when the combined storm water and sewage flow is greater than the combined system can handle causing a Combined Sewer Overflow (CSO). In this case, the flow is released into the river or lake, being treated with only chlorination. These occasions have been reduced and are continuing to improve. See Image below. **Please note that our combined sewer systems also include holding tanks and other upgrades to prevent CSOs from occurring. All CSOs are carefully monitored and recorded. See reverse for details. 1

2 What is stormwater pollution? Most of our rainwater travels through gutters, storm drains, channels, washes and eventually into the major source of our drinking water, Lake Ontario. The largest source of stormwater pollution in Kingston results from every day activities. The most common pollutants are: Trash (fast-food wrappers, cigarette butts, Styrofoam cups, etc.) Contaminants (used motor oil, antifreeze, fertilizer, pesticides, sewage overflow, pet droppings, etc.) These pollutants are picked up as water (from rain, hoses, sprinklers, etc.) drains from streets, parking lots, and lawns and enters the thousands of catch basins throughout the City of Kingston. From there, these pollutants flow through a massive system of pipes and open channels straight into Lake Ontario or the Cataraqui River. Anything dumped or dropped on the ground or in the gutter may contribute to stormwater pollution. We can directly reduce the amount of pollution entering Lake Ontario by catching the water before it enters the storm drain by soaking it up in our own yards. Likewise, by reducing our dependence on storm drains and eliminating extraneous flows to the sanitary sewer system we can reduce or event prevent flooding and combined sewer overflows during extreme rain events. This workshop will cover many common techniques that homeowners can employ to benefit our community in many ways: Improve quality of our drinking water Benefit wildlife by creating new habitat Protect our city from flooding in extreme weather Prevent beach closures from pet waste contamination Prevent stormwater pollution in all local waterways Table: Historical Combined Sewer Overflow Totals Updated: 06/06/2013 Year Events Volume (m 3 ) Precipitation (mm) , , , , , ,588 N/A (2) , ,381 (1) For some events in September and October 2006, volumes were unknown. (2) 2008 rainfall data unavailable until after mid-june; therefore, total is N/A. Source: Utilities Kingston website, June 2013 PART ONE: DOWNSPOUTS AND THE PREVENTATIVE PLUMBING PROGRAM (PPP) We know a lot more about water pollution now than we did when downspout sewer connections were first installed. By allowing clean water to disappear into storm or sanitary drain, we are treating it as waste, which is no longer necessary. By-Law was written to ensure that rainwater is not treated as waste. Your soil acts as an effective natural water purifier once we understand how to guide it to the places it will be best used! Climate change predictions for our region show that we will be receiving more frequent and heavy rain. By taking care to ensure proper drainage on our own properties, we do our part to ensure the health of our waterways while protecting our own property from flooding. LEFT: A couple examples of illegal connections to the sanitary sewer. Image credit: Institute for Catastrophic Loss Reduction 2

3 A GUIDE THROUGH YOUR HOME DRAINAGE Image Credit: Institute for Catastrophic Loss Reduction o Downspouts o Carries water off your roof to a safe distance from your foundation. Now illegal to connect to sanitary sewer by-law Sewer Lateral o Weeping Tile Collects water from around your home draining into Sump Pit from all below home drainage Connection to storm or sanitary sewer is against By- Law o Should be inspected every 5-10 years Connects your home to the sanitary sewer. Homeowner is responsible for maintenance up to edge of property line Always has a minimum 2% grade Video Inspection is an eligible PPP cost Backwater Valve Prevents water from back-flowing into your home Follow manufacturer s suggested maintenance schedule Is an eligible PPP cost if you don t already have one installed o Disconnecting from sewer can be expensive and is an eligible PPP cost. Utilities Kingston is available to help identify issues with a free home visit Sump Pumps and Pits Pump water that has collected underground from your basement or around your foundation Have alarms that tell you when they aren t working It is recommended to have a backup pump and power source Follow manufacturer s suggested maintenance schedule 3

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6 What you ll need: Hacksaw Tape measure Screwdriver and/or drill Pliers Sheet metal screws HANDS-ON TUTORIAL: DOWNSPOUT DISCONNECT Rubber cap or PVC cap Downspout pipe extension of your choice Brackets to secure downspout to building Work gloves Safety Glasses Sewer lateral cap Step one: Measure 23cm (9 ) from where the downspout enters the sewer connection. Step two: Cut the downspout with a fine blade hacksaw. Make sure to remove the cut piece and do not drop it down the drain. Use a metal file to remove the rough edge of the downspout. Activity: cutting downspout for practise. Step three: Be sure to cap the sewer standpipe -- the open pipe remaining when the downspout is disconnected. This prevents water from going in. It also stops animals from falling into the opening, getting trapped, and having to be rescued. You can use a simple rubber cap secured by a hose clamp, PVC cap or a wingnut test plug and concrete if available cap sizes don't fit. Step four: Insert the downspout into the elbow (if you put the elbow into the downspout, it will leak). You may need to crimp the end of the downspout with a pair of pliers to get a good fit. Activity: fitting pieces together Step five: Attach a downspout pipe extension to carry water away from the house and foundation. You can use a hacksaw to cut the extension to the desired length. Be sure to insert the elbow into the extension to prevent leaks. Drill a hole on either side and secure the elbow and extension with sheet metal screws. To prevent erosion where the water drains, you can place a splash pad at the end of the downspout extension or use flexible pipe that can be moved occasionally. OPTIONAL BONUS: Your newly directed downspout can empty into a rain garden, bioswale or trench of your design. ALWAYS MAKE SURE YOU CAP YOUR SEWER CONNECTION! 6

7 PREVENTATIVE PLUMBING PROGRAM Utilities Kingston is available to help you solve any drainage issue you face; stormwater and drainage affect us all in extreme weather. Staff is on hand to offer a number of free services to help you out: Home visits to help identify and solve drainage issues Assessment of your property to determine which improvements qualify for funding Offer financial incentives to make plumbing improvements more affordable for your family Please refer to the attached brochures while we go over this section! For more information on Preventative Plumbing Measures please visit PART TWO: RAINSCAPING CALL BEFORE YOU DIG! Before starting any excavation project, it is your responsibility to make sure you are not interfering with local drainage, utilities, or sensitive wetland and waterways. Here are some phone calls you must make while planning your rainscaping system: Ontario One Call o Call at least one week prior to digging to have underground utility lines marked on your property. o or use their online form at City of Kingston Planning Department o Ask for the drainage plan for your neighborhood to ensure your system works with it and not against. o Phone: , Ext Cataraqui Region Conservation Authority o Your yard work may be impacting sensitive waterways or wetlands nearby! Please make a quick call to The CRCA to determine if you need a permit for what you d like to do. o Call Tom Beaubiah at (613) ext. 240 or toll-free (in 613 area code) CRCA ext RAINSCAPING MATERIALS See Appendix for availability and pricing of these items. Gravel has large voids between the stones where water can be stored, approximately 40% of the gravel volume. By digging a hole, adding a liner of landscaping fabric, and regularly cleaning debris you can effectively create water storage (see soak-away pit ) until it has a chance to be released into the soil. By filling graded trenches with gravel, you can move excess water around your property. Make sure to use Washed Gravel (we recommend ¾ clear) so it doesn't come pre-clogged with dust. Leave 2-5 cm between gravel and top of trench. Add decorative large river stones on top to ease seasonal cleanup and to make the trench unable as a walkway. Soil There is more difference between types of commercially available soil than you may think. #1 7

8 Topsoil a mix containing 80% sand and is the most commonly used by contractors. If you have clay soil you may inadvertently create concrete by adding this type of soil on top. When amending your soil, be sure to ask for a Lawn mix because it contains a higher percentage of organic matter. Yard Mulch acts like a sponge and slowly releases water into the ground. You can add new mulch (grass clippings, small branches, wood chips, leaves) every year when you are doing yard clean up to maintain its effectiveness. As a bonus, it's a great way to get rid of yard waste! Mulch slows irrigation peaks, reduces erosion, slows movement of runoff. You can create a donut mulch basin outside the canopy of a tree (to avoid roots) and the water will be time released. This type of basin can absorb 20 litres per m 2 per week! Store Bought Mulch is a nice finishing touch in a rain garden, but should not be used the same as yard mulch. It has limited effectiveness in deterring weeds and too much can choke out the beautiful trees and shrubs you want to grow! Always leave a minimum 6 radius around all plants and you never need more than a 2-3 layer at any time. When adding new mulch, remove the old mulch to your compost pile or green bin and because too much decomposing matter can have negative impacts on your garden. Landscaping Fabric OR Newspaper can be used to wrap gravel drainage areas thereby preventing premature clogging. When using newspaper, be sure to use layers. An added benefit of using newspaper is it will allow for lateral infiltration into neighbouring garden beds. Commercial landscaping fabric must be replaced every 5-10 years whereas newspaper will gradually decompose on its own. Perforated pipe (Big O) will increase a trench s capacity to convey water by creating more OPEN SPACE (as opposed to gravel which fills 60% of space). It also spreads out the area where water can seep into the soil. Lay in the bottom of trench with holes facing down. Cover with gravel. Non-perforated pipe (Big O or ABS pipe) directs water without allowing for infiltration. Rainbarrels are a great way to store 200L+ of water for use at a later time. Make sure to empty them out regularly in order to increase water quality, maintain their capacity to handle run-off, and make use of free water! Splash pads are a great way to reduce erosion and direct downspouts or overflow water from rainbarrels towards one of the techniques described below. Downspout extensions are easy to find and come in a wide range of colours and styles. They are designed to direct rainwater in a specific direction or to a selected spot. Ideal for rain gardens and swales. Leaf Eater Also known as a Rain Head Screen, These divert leaves from clogging up your rainwater system. TECHNIQUES Rainscaping starts a minimum of 3m from your house. Never direct water towards a neighbour s 8

9 property. 2% Slope is important when draining water. You'll also want to make sure the ground below your water discharge is evenly graded downward. Otherwise, you risk having sections of the pipe where the water pools up and either collects debris and clogs, or freezes. Depending on your yard, if achieving a 2% pipe slope is difficult installing one of the other measures listed may solve this problem. Other methods of directing water such as a swale or trench do not have the 2% rule. Activity: demonstrate use of line level. If you have steep or unstable slopes on your property, be sure to consult a professional. Trenches (or French Drains) are typically between 25cm to 1m deep, and 30cm to 1 m wide, can be any length filled with gravel and/or pipe. They are sloped to direct water from one end to the other, and are used to direct water away from foundations to rain gardens, swales, or a soakaway pit. A drop of 2.5 cm for every meter in length is enough to move water. Avoid leading water to the sidewalk or street. A spade can help you achieve a consistent slope to prevent pooling. Swales Bioswales are biological filtration canals. Like trenches, they are designed to soak up water while allowing it to move away from foundations and walkways. They are shallow and wide, with vegetation growing on bottom. They tend to be larger than trenches, and thus require more space, soil removal, materials and planted vegetation, but can handle much larger volumes of water. Soakaway basins are vertically oriented (deep) and filled with mulch, plants or active compost. They are meant to convey water deeper into the ground and act as storage capacity. Especially useful for small lots or when poor drainage is found. Trenches can end at a soakaway basin. Locate at least 4 m (13 ) from house foundations or sensitive areas. Plastic Drywells have perforated walls, are surrounded with gravel and can act as passive rain storage for those who want to hide their rainscaping system under their lawn. These are best installed by a professional landscaper. Constructed Wetlands are designed to mimic the natural cleansing processes of wetlands. They usually consist of a series of pools, each one progressively improving the water quality. They require a significant level of expertise to properly create. Soil Amendment You can dramatically increase your lawn s capacity to hold soil by adding thin layers or organic matter once or twice per year. You can use finished compost, aged manure, or shredded leaf litter and yard waste depending on your desired use. Spring or fall is the best time to do it. Add a maximum of ½ cm so that you don t overwhelm existing lawn/garden. SIZING YOUR SYSTEM Activity: Walk through of the stormwater calculation sheet. RAINSCAPING MAINTENANCE 9

10 Leaves, twigs, gravel from asphalt roofs can clog up rainwater infiltration systems. Use rain barrel as a filter Cut back branches that hang over the roof Clean and maintain eavestroughs or install gutter guards A rain head screen can reduce the amount of leaves in your system Keep the splash pad clear of sediment Check regularly, especially after major rain events Regularly remove debris from gravel systems In cold climates, freezing can be a concern. Here are some possible solutions: Dig a deeper trench Use heat tracer tape on pipes Install a drywell Insulate the trench Use a larger pipe Ensure proper slope to prevent ponding APPENDIX: RAINWATER SUPPLIES AND WHERE TO FIND THEM Item Size Price (each) Notes on selection and availability Mulch Decorative Mulch 2Cubic Feet or 56Litres $3 - $11 Wide Availability Yard Mulch As much as you can make Free! Leaf Shredder/Mulcher To Rent Up to 6 Branches $175/4hrs Widely available equipment rental To Rent Up to 6 Branches $250/day Widely available equipment rental To Purchase Leaves, needles, grass, paper only $200 & up Order in from major department & hardware stores Order in from major department & To Purchase Up to 1 1/2 branches $169 & up To Purchase Up to 2 1/4 branches $699 and up Pipe hardware stores Order in from major department & hardware stores Big O 4" X 10' $8 - $17 Big O 4" X 100' $70 Note: Large orders must be specially ordered - may take two weeks ABS Plumbing Pipe 1 x 100 $40 Wide Availability at hardware stores Rainbarrels Plastic 200 Litres $40 Available to UK customers w/ 10

11 delivery Plastic 200 Litres $65-$150 Large Selection of colours and styles 400 Litres Splash Pads Typically 24x12x2 1/2" Plastic $11 - $20 Wide selection of shapes and styles Concrete $9 and up Commonly moulded concrete or pebble finish Downspout Lengths Call to stores ahead of time to ensure availability Curved 2x3" - 3x4" $13 - $15 Straight 2x3x15" $3 - $6 Tube Style Expandable $10-$15 Designed to fit to downspout Poly roll-up style 5 to 12 styles $3-$15 Gravel Pea Size 3/8" 18kg Bag / 30kg Bag $6-10 Wide Availability at Gravel 1/4" to 1/2" size 30kg Bag $8-10 building/construction focused hardware stores Soil Garden supply or Landscapers #1 Topsoil 1yd 3 $22 Drains quickly, low moisture retention Lawn Mix 1yd 3 $28 Higher moisture retention Compost Finished municipal 20 Litres $4.50/bag Norterra Organics Finished Home As much as you can make free Sewer Connection Caps Plumbing Supply shops can help you out with an unusual fit CSA Approved Cap Depending on connection style $2-$12 Hardware stores Big O end Cap $3 Hardware stores Gutter Guards Catches leaves before they enter the gutter Stainess Steel 10 pieces $12 - $ 50 Widely Available at hardware stores Plastic 25 roll $5 Widely Available at hardware stores Rainhead Screen A little harder to find $10-$100 Dependant on screen quality Adapters and Connectors Downspout to 4 pipe $2-3 Widely available Downspout Diverter Switch style $25 and up Downspout Diverter Y-Style Hose Clamps All sizes $0.25 to $3 each For connecting all sizes of flexible pipes together. Widely Available 11