WASTEWATER TREATMENT AND DISPOSAL SYSTEMS SERVING SINGLE HOUSES

Transcription

1 WASTEWATER TREATMENT AND DISPOSAL SYSTEMS SERVING SINGLE HOUSES Read this before you begin using your sewer Miljö & Hälsoskydd Kungsbacka kommun Kungsbacka

2 Your wastewater must be treated We use water every day. We shower, wash dishes, do laundry, and flush toilets. The used water from bathing, washing dishes, laundry, and toilets is called wastewater. It must be treated before we can use it again, regardless of whether it was used in a bathroom sink, a kitchen sink, a washing machine or a toilet. Dirty water causes eutrophication Nitrogen and phosphorus, both nutrients, are found in wastewater. When they enter our watercourses, lakes, and oceans, they cause eutrophication with algal blooms and lack of oxygen as a result. Eutrophication has adverse effects on bottom-dwelling animals, and in certain cases fish as well. Dirty water can make us sick If drinking water or bathing water is polluted by wastewater, we could become sick. Nitrates are found in waste water; they are hazardous in high amounts, especially to children. There may also be bacteria and viruses. This is why it is important that your system treats waste water sufficiently before it reaches groundwater or surface water. You are responsible for your sewer If you own property that is not connected to the municipal water and sewer system, you must ensure that your wastewater is treated. Your sewerage system must be installed by an expert. Depending on where you live and what the system will be used for, you will either need to apply for a permit or fill out a written report. Contact Environmental and Health Protection as early as possible, and we will help you with the process. You can find more information at Questions about contracts and consumer regulations Contact Consumer Guidance through the Kungsbacka Direkt municipal customer center at +46 (0) or info@kungsbacka.se Which rules apply? The Swedish Environmental Code (SFS 1998:808) and the Ordinance concerning Environmentally Hazardous Activities and Protection of Public Health (SFS 1998:899). The Swedish Environmental Protection Agency has published general guidelines (NFS 2006:7) on small wastewater appliances for household wastewater. Kungsbacka Municipality has a strategy for private sewers (NMH , 6). You can find this at 2

3 Permits and reports Permits If you are going to install a new sewer with a water closet, you must have a permit. This also applies to bathing, dishwashing, and laundry systems west of the E6 motorway as well as to dry toilets, for example composting toilets and incinerating toilets. Your application Your application should include the following: A layout plan: a simple sketch map on which buildings, roads, water courses, water supplies, property lines and any geothermal wells are marked. Also draw the various parts of the sewerage system. Environmental and Health Protection needs a map in 1:400/500 scale, as well as one in 1:2000 scale, on which your neighbors water supplies are also drawn, with distances. A description of how the system is designed. A longitudinal section drawing, if there is a landbased system such as infiltration or sand filter. Distance to own and neighbors water supply, surface water, ground water, and any geothermal wells. The manufacturer s instructions regarding operation and the design/function of the system must be attached for a technologically advanced system for example a mini purification system, graywater filters, or a system with biomodules. Written approval from the landowner, if all or part of the land the system will be located on is owned by someone other than yourself. Information on who will handle servicing the system if such is required, for example a service agreement or certificate of expert knowledge. Report If you are going install a sewer without a water toilet, as a rule filling out a report will be enough. This also applies to bathing, dishwashing, and laundry systems east of the E6 motorway. Contact Environmental and Health Protection to find out what applies to your property. If you are thinking of renovating or making changes to your existing system, contact Environmental and Health Protection for more information. Keep in mind As the property owner, you are responsible for producing and attaching the documents required. You are also responsible for the information you submit being correct. If you neither have a permit nor have filled out a report and nevertheless begin installing a sewerage system, you may be forbidden from using the system or be required to change it. This is done if Environmental and Health Protection judges the location to be unsuitable. You must also pay an environmental sanction fine charge of up to 5,000 SEK. 3

4 The application Contact Environmental and Health Protection through the Kungsbacka Direkt municipal customer center, at +46 (0) or This is you Contact an expert contractor. If you are going to have a subsurface treatment system, dig at least two trial holes at least two meters deep. Book a time with Environmental and Health Protection for a visit to the property. Preliminary investigation This is Environmental and Health Protection Environmental and Health Protection will arrange a visit during which we will conduct site assessment and evaluate the conditions for the system. We can conduct this visit before or after you have submitted the application. Fill in and submit your application, together with attachments, with a layout plan to Environmental and Health Protection. Read through the conditions in the permit, and forward the conditions to the contractor. Permit application Environmental and Health Protection will go through your application and request supplementation if needed. When the application is complete, we will take either a positive or a negative decision. If there is a risk of impact on a neighbor, we will send the application to your neighbors for their viewpoints. They will have a few weeks to submit any views. If you are given a positive decision, it will involve a number of conditions. A inspection plan will be attached to the permit. If necessary, a final inspection will be conducted. The contractor will start off the work by installing the sewer. Document the work in the inspection plan, and photograph all parts of the system. Execution Contact Environmental and Health Protection for any final inspection. The contractor will fill out the inspection plan. You will sign the inspection plan and send it together with any attachments, photos and documents to Environmental and Health Protection within 14 days. Environmental and Health Protection will review the inspection plan and contact you if information is missing. The property will be entered into the registry for sludge removal. With that, the case is completed and you will receive a certificate that the sewer is in order. Environmental and Health Protection will then inspect the system on a continual basis. 4

5 Submitted application Positive decision If your planned sewerage system meets the requirements for treatment, we will either give you a permit or a response to your report. With this decision, you will be given a number of conditions and advice on how to construct and operate the system. When you have received your decision, you will be given two forms from us: an inspection plan and a certificate of execution. Once the system is ready, you must submit the forms to us together with photos, a new map (if any) and, if necessary, an agreement with the contractor who will handle servicing. The agreement must be signed. Keep in mind that if your neighbors were allowed to submit their views, you cannot start the work on the system until the case has entered into force, which is normally after three weeks have passed. Inspection plan The inspection plan is specific to each property. It must be filled in on a continual basis by the contractor performing the work, during the period in which the system is being installed. The design of the system is documented in this manner. All parts of the system must also be documented with photographs. Certificate of execution By signing the certificate of execution, you and the contractor swear that the system has been designed in the way stated in the application or report and in the decision you received from ups at Environmental and Health Protection. If anything has changed or differs, you must write this in the certificate of execution. Other documents you must submit If you have used filter sand or any other type of sand in the system, you must attach a screen analysis together with your inspection plan and certificate of execution. If you have a system that requires a journal sheet, operation and maintenance instructions, or the like, you must attach these documents. Also attach a map of the location, if something has changed, and a landowner s affidavit if parts of the system are placed on anyone else s land. Final inspection Once everything is finished, you must contact us at Environmental and Health Protection so that we can conduct a final inspection of the sewerage system. In certain cases, we will not need to conduct a final inspection. An inspection plan, photographs, and certificate of execution will be sufficient as an account. We will inform you of this when you contact us for final inspection. When the system is finished and all documentation has come in, we will examine the documents. After that, you will receive a certificate for the system. We will also send the certificate to the sludge removal contractor and to the Technical/Mechanical Administration so that they have the correct information about your system and so that you will have annual removal. Negative decision If we feel your sewerage system does not meet the requirements for purification, there are two alternatives. Either we will give you the opportunity to bring a new proposal for what the sewerage system should look like. You can do this in consultation with us. Or your application will be rejected. If you receive a rejection, you can appeal the decision. We charge a fee Regardless of what decision you are given, we will charge a fee for handling the case. The rates are established by municipal councillors. We also charge an annual fee for technologically advanced systems mini purification systems, for example. What should I keep in mind during installation work? Check against the permit issued, and against the contract, that the work is being performed as it should. If the conditions for the sewer have changed since you received the permit, for example though discovering a large stone in the way, heights having changed, a new well for drinking water has been added, or the like, contact Environmental and Health Protection. See to it that the inspection plan is filled out by the contractor, and that the work is photographically documented in accordance with the plan. Call for final inspection four working days in advance, if these conditions are found in the permit. You should preferably be present during the final inspection. When the system is ready: send in the photographs, the filled-out inspection plan, the certificate of execution and any other documents, for example a new situation plan or certificate of expert operation to Environmental and Health Protection. 5

6 Your surroundings Find out your protection level Location is important so that your sewerage system does not have an adverse effect on its surroundings too much. The type of system you will have depends on a number of different factors. Where you live in the municipality affects the requirements for your sewerage system. In an area with a high level of protection, the requirements for the efficiency of the treatment are higher. Contact Environmental and Health Protection to find out what applies where you live. Regardless of protection level, we assess each case on its own. High protection level nutrients nitrogen and phosphorus. These substances contribute to eutrophication, leading to a shortage of oxygen that could push out benthic animals and fish. Above all, nitrogen and phosphorus come from agriculture and faulty private sewers. We have a high level of protection in nearly the entire municipality in order to reduce eutrophication in our waterbodies. A high protection level can also apply to health protection, if your property or the system s discharge point is located close to a swimming area or lake, within a water protection area, or close to Strategi för små avlopp 2014 neighbor s water well. Many of Kungsbacka s lakes and water courses, and our coastal waters, have elevated levels of of the Protection levels l High protection level l Normal protection level l Normal protection level zone Oxsjön and Stora Hornsjö 6 Normal skyddsnivå med skyddszon runt Oxsjön och Stora Hornsjön

7 Keep in this in mind when selecting sewers Think the placement through There is always a risk of a sewerage system polluting ground water or surface water, or causing some other nuisance. That is why a protective space around the system is important. See to it also that you plan for how to get your drinking water. Lakes, oceans, or water courses There should be a safe distance to lakes, oceans, or water courses of at least meters. If the land slopes sharply, a greater distance may be needed. Roads, paths, or property lines The sewerage system should not be located closer than four meters from a road, path, or property line. If your neighbor consents, the system can be placed closer. Water wells There must be a safe distance to nearby water wells. The distance between the sewerage system and the water well should be between 20 and 200 meters, depending on the type of system, the water well, and the terrain. If the distance is judged to be too short, you may need to install a compact system or move the discharge point elsewhere. Energy wells To reduce the risk of pollutants being conducted down into groundwater near an energy well, the distance between the discharge from a sewerage system and an energy well should be at least 30 meters. The energy well should be placed higher on the terrain than the discharge point of the sewer Bedrock and groundwater The distance to bedrock and to the highest groundwater surface from the underside of the dispersion layer should be at least one meter. Keep in mind that the groundwater surface may vary during the year, and even be raised under the system. It is therefore important that the system not be placed too deep. longer, an extra fee will be charged. Hire an expert Knowing how big the protective area needs to be requires different types of investigations. It is preferable that you hire an expert contractor early on. If conditions on the property are complicated, Environmental and Health Protection can additionally require that an expert be hired in order to conduct a geological investigation, for example if the distance to water wells is short. If the material in the ground is difficult to assess, a screen analysis may be required. Investigations are required DetThere are no requirements that you must use a certain kind of technology to treat wastewater. On the other hand, there are requirements on the function of the system. The goal is always that wastewater will always be treated as best as possible. Before you decide on which treatment technology you want to use and where the system is to be placed, you must find out the prevailing conditions on your property. The investigations should be conducted by an expert. The results are to be accounted for in the application to Environmental and Health Protection. To be marked on the situation plan By digging a trial hole, you will find out about the natural conditions for infiltrating the water. The factors investigated in connection with a trial hole survey are ground slope, placement of water supplies, distance to surface water and water courses, and soil properties. If the conditions are difficult to assess, you as the applicant should take a soil sample for screen analysis. The sample will be sent to a laboratory for analysis. Environmental and Health Protection may take a decision if needed. Parking space The distance between the septic tank, or the closed tank, and the parking space for the sludge removal truck may not be greater than 20 meters. If it is 7

8 Which systems will work in your location? In this table, you see examples of systems that, in normal cases, are approved in normal and high protection levels respectively as regards both existing and new systems. System type Normal prot.level High prot. level High prot. level Note that a location near a shore, or risk of impact on for example a water supply or bathing area, can entail requirements for a higher protection level than normal. Existing systems where toilets have had permits from earlier and have been installed New systems where toilets do not have permits from earlier and are not installed, or if it concerns a secondary residence Requirements for separate collecting of water from toilets. Infiltration (with toilet) Yes No No Sand filter (with toilet) No No No Sand filter + phosphorus trap (with toilet) Packaged wastewater treatment systems + posttreatment (with toilet) Extreme low-volume flush toilet (under 1 liter flush volume) to closed tank + infiltration, sand filter or filter for grey water BDL* Closed tank** for toilet with over 1 liter flush volume + infiltration, sand filter or filter for grey water BDL* Urine-diversion dry toilet + infiltration, sand filter or filter for grey water BDL* Multrum + infiltration, sand filter or filter for grey water BDL* Incinerating toilet + infiltration, sand filter or filter for grey water BDL* Yes No No Yes Yes No Yes Yes Yes Nej No No Yes Yes Yes Yes Yes Yes Yes Yes Yes * grey water means bath, dishwashing, and laundry water. ** A common toilet with a closed tank is approved in normal cases as a temporary solution while awaiting a municipal connection.. 8

9 Treatment in several steps Treatment of wastewater occurs in several steps. The most common components needed are a septic tank, a pump, and a distribution chamber. Septic tank Most sewerage solutions need a septic tank, and a number of them also need a mini treatment system. That is to say, the large particles in the wastewater need to be removed so that the subsequent treatment stage is not destroyed by clogging. In certain sewerage systems, the septic tank is included in the product itself. Septic tanks the most common A septic tank can be made of plastic, fiberglass, or concrete and must be CE-labelled that is, quality-assured. The most common septic tank is the concrete septic tank. There are also newer plastic variants of septic tanks that have a different construction than the usual three chambers. Several sizes The most important thing to keep in mind when selecting a septic tank is that the volume is sufficient. The size of the septic tank depends on the size of the household that is, how many people live in the household. For one household (one to five persons) with a water toilet, a septic tank of at least 2,000 liters is required. If the system is intended only for bath, dishwashing, and laundry water, at least one septic tank or a tank with a volume of approximately 1,000 liters is required. Regular emptying Emptying of septic tanks is done by a Kungsbacka Municipality contractor once a year. It is possible to order extra sludge removal. There is also a possibility of having sludge emptying every other year, if the sewerage system is only for bath, dishwashing, and laundry water and the volume of the septic tank is at least 2,000 liters or for a summertime/ part time residence with a low level of use. Exempts can be granted other cases as well. Pump If there is no natural gradient on the property, a pump may be required to conduct the wastewater further on into the treatment process. How large of a pump chamber you will need depends on how much water will be running through it, but for one household the reserve volume must be at least 500 liters. It is important that it be possible to check that the pumping works. You therefore need an alarm connected to the pump. Distribution chamber A distribution chamber is most often needed after the septic tank. The distribution chamber distributes the wastewater evenly among the dispersion pipes. The chamber must have the function of moderating the incoming water, and the outflow must be adjustable. Closed tank Closed tanks with vacuum toilets or similar, where the flush flush volume is at most 1 liter per use, are accepted. Existing closed tanks are acceptable. But in most cases, a common flush toilet with a closed tank is an emergency solution and is not normally approved. A closed tank is most often used only when nothing else works, for example owing to dense settlement or difficult soil conditions. A closed tank can also serve as a temporary solution while awaiting a municipal connection. Rainwater and drainage water Rainwater and drainage water may not be routed into the wastewater appliance. The water should be collected in a separate pipe and released into the soil or a ditch. It is also possible to let it run together with wastewater after it has been treated, for example in a sand filter. Backflush water Backflush water from water purification filters may not be routed into the sewerage system, as it risks quickly stopping up the system. Think about what you pour into your wastewater Sewerage systems cannot handle petroleum products, solvents, leftover paints, and the like. Nor are most systems dimensioned for large flows over short periods. You should therefore be observant, for example if you are going to install a jacuzzi. The flow of water then needs to be restricted so that it empties slowly. Connecting an outdoor pool to the system is not permitted. 9

10 Which technology suits you and your property? Packaged wastewater treatment systems Packaged wastewater treatment systems vary widely in size, cost, and appearance. What they have in common is that the treatment process is automated, and that it occurs in a closed system. The wastewater is then routed out to a ditch, drainage system, or water course. Some purification packaged wastewater treatment systems require a septic tank, but others do not. In most packaged systems, the water is first pretreated through sedimentation that is, particles found in the water are sorted out. After that, the water is biologically treated to reduce the amount of organic material and nitrogen. Chemicals are added to separate out phosphorus. A polishing stage is often required as a final step of the treatment process. For example a polishing stage could be a sand filter. Contaminants such as bacteria are purified out from the wastewater in the sand filter. There can also be simpler options such as a stone caisson or a macadam ditch. Reporting requirements The requirements for a person who wishes to install a packaged wastewater treatment system are great. Apart from expert maintenance, as a property owner you must also have self-inspections and keep a journal of operation. Upon request, you must be able to show service records, a receipt for purchase of precipitate chemicals, and reports on your self-inspection for Environmental and Health Protection. Infiltration In an infiltration system, wastewater is treated though being filtered out in the natural layers of soil. The treated water is then distributed into the groundwater via the soil. Are there natural conditions? To find out about the natural conditions for infiltrating the water, you need to dig a trial hole. The trial hole is dug near the location where you intent to place the system. To find out whether the soil layers are permeable and well-drained, a soil inspection is conducted. A soil test may sometimes also need to be conducted. Infiltrations require that a groundwater pipe is connected to the filter bed. The purpose of the pipe is so that you, as the property owner, and the inspecting body are able to check that the system is not standing in the groundwater. The design and so on must be accounted for in the application. In an infiltration system, water is purified in the natural soil. In a sand filter, the sand layer is constructed with special filter sand since the natural layers of earth are too dense to permit infiltration. Konventionell vattentoalett Slamavskiljare Infiltration 10

11 Filter sand If the soil consists either of entirely too fine or too coarse-grained material, placing filter sand under the diffusion layer a reinforcement layer may work. If the groundwater level is high or the distance to the bedrock is small, the infiltration can be raised. Groundwater pipes are needed To check whether the infiltration impacts the groundwater, the infiltration bed is equipped with a groundwater pipe. This pipe serves as a peephole through which samples can be taken. The difference in level between the dispersion layers and the bottom of the groundwater pipe must be at least 1.2 meters. Protective area There must be a protective area of at least one meter between the underside of the dispersion layer and the highest groundwater surface level. Sand filter In principle, a sand filter is built on the same process as an infiltration system that is, wastewater is treated by running through a sand layer. The difference is that the sand layer is constructed with special filter sand since the natural layers of earth are too compact to permit infiltration. At the bottom is a collection pipe that conducts the treated wastewater away to a ditch, river, lake, or ocean. Problems with gravity draining The bottom of the sand filter lies deep, usually at just over two meters. It can therefore be difficult to use gravity draining on properties that have little to no ground slope. It is possible to overcome the problem through installing a pump. Phosphorus purification Only a sand filter in itself does not meet the requirements imposed for treatment of water that comes from a toilet. In order to meet the requirements imposed in an area with a normal protection level, the sand filter needs to be supplemented with phosphorus purification. Biomodules/Compact filters Instead of a diffusion filter in an infiltration system or sand filter, you can use biomodules or compact filters. These break down organic materials. Biomodules are placed in sand filters and infiltrations, and exist for both water from toilets as well as for bath, dishwashing, and laundry water. Compact filters can be used for the treatment of bath, dishwashing, and laundry water. If there is a shortage of space on the property, compact filters can reduce the surface area of the filters. A compact filter requires more maintenance by the owner, and in some cases service by an expert. You may also need a composting system. Note that there is no testing standard for compact filters. On the other hand, there are CE-labelled pre-fabricated systems that include biomodules. Vacuum toilets A vacuum-flush toilet has extremely low-volume flushes; it looks like a common flush toilet and is used like one. Flushing occurs through negative pressure in the pipes, and the water is used only to clean the toilet bowl. A vacuum toilet system is robust, and operating costs are relatively low. We manage emptying You will need a closed tank for a vacuum toilet. The advantage of a vacuum toilet is that you reduce the number of sludge removals per year and that there are no onsite emissions. There are also the conditions for circulation. Sludge removal is carried out by municipal contractors. Bath, dishwashing, and laundry water is treated separately Treating wastewater from baths, dishwashing, and laundry requires a separate system such as. for example, a septic tank, a sand filter, or infiltration. Urine diversion A urine-diversion toilet has two collection basins. Urine is collected in the foremost one, and fecal matter in the rear one. The urine mixture is routed to a collection tank via a separate pipe system. The tank must be dimensioned for one year s discharge, which means cubic meters per household. You can handle the urine yourself Kungsbacka Municipality does not conduct urine collection. On the other hand, you can get a permit to handle the urine yourself. It is also possible to sign contracts with farmers. Note that urine diversion with water toilets is only permitted in areas with normal protection levels. Large portions of Kungsbacka Municipality have high protection levels. 11

12 Dry toilets Dry toilets handle toilet waste in a different way than releasing wastewater. Water from baths, dishwashing, and laundry must be treated separately. Permits are required in accordance with local regulations for the installation of dry toilets. Incinerating toilets An incinerating toilet normally does not flush with water; a bag is used for every visit. Upon flushing, the bag falls into the incineration chamber in the toilet. The only thing that remains is a bit of ash that can be used as fertilizer. Composting toilet In a composting toilet, all waste is collected in a large container and is decomposed biologically. The waste is stirred regularly in order to speed up the decomposition. The resulting soil is left to compost in an airtight container for at least two years. After that, it can be used as fertilizer. Phosphorus purification Phosphorus purification can be designed in two different ways: either through a phosphorus trap or through phosphorus precipitation. Phosphorus precipitation Phosphorus purification is a chemical precipitate that binds phosphorus and particles in gelatin-like clumps that sink to the bottom of a septic tank. The technology means that the septic tank must be cleaned more often, or alternately that the size of the septic tank must be larger. The technology requires electrical installations for chemical precipitation and control. An expert must install the system and optimize it for operation. The service must be handled according to the manufacturer s instructions, which sometimes means that it needs to be done by an expert. Phosphorus filters in phosphorus traps Treatment in a phosphorus filter is built on phosphorus in the wastewater being bound, for example to a lime filter. The trap is placed after a dense sand filter. The filter must be dense enough in order for the phosphorus trap to work. Several products on the market consist of filter cassettes that can be emptied, in which the filter mass is replaced on a regular basis, usually every other year. Loose filter material is sucked out with the sludge, while larger bags are replaced using a crane lorry. What should I keep in mind once the work is completed? See to it that you receive operation and maintenance instructions from the contractor or supplier. If you have a packaged wastewater treatment systems and similar systems, the supplier must also be able to give you a form for an operation journal as well as instructions for sludge removal. Place the sludge removal instructions close to your system so that the emptying contractor does it correctly when it is time for sludge removal. Assemble all documents concerning your sewerage system into one binder so that they are easily accessible. What should I keep in mind once the system is in operation? SAs property owner, you are always responsible for service, maintenance, and operation of the system. You must see to it that the system functions as intended, and that it is serviced and maintained. For example, it is not possible to cite the fact that a company did not comply with a service agreement; as property owner, the responsibility is always yours. Different systems have different service needs. Read your wastewater permit and service instructions. Certain systems packaged wastewater treatment systems for example require frequent supervision intervals and that you have a service agreement or the equivalent