* Table of Contents:
Table of Contents: 2
1.0. Introduction: 3 1.1. Provincial Regulations, Standards and Application Process: 4
2.0. Discussion: 6 2.1. File Review and Site Inspection 6 2.2. Site Evaluation: Soil Suitability and Percolation Test 8 2.3. The Septic Tank: Function, Design and Inspection. 10 2.4. Distribution Box: Function, Design and Inspection. 12 2.5. Absorption Trenches: Function, Design and Inspection 13
3.0. Conclusion: 16
4.0. References: 18
5.0. Additional Resourses: 19

Introduction:
The World Health Organization estimated in 2013 that roughly one-quarter (or 2.4 billion) of the world’s population shall lack access to “Improved Sanitation Facilities” in 2015.(7) Improved Sanitation Facilities are those that help eliminate human contact with sewage, and include flush or pit toilets/latrines and composting toilets.(1) In many regions of the world (even when such facilities are available) untreated sewage is often discharged into drains and streams, due to lack of expensive collection and treatment infrastructure. Thus, surface water surrounding many urban areas in the world remain grossly contaminated with fecal matter, and often contamination seeps into groundwater.(1)

Waterborne communicable diseases such as Cholera, Typhoid, Dysentery, Hepatitis A, Schistosomiasis, or Intestinal Nematode infections generally spread through fecal-oral route. Potable water contaminated with untreated sewage poses serious health risks to humans as it can contain different waterborne pathogens (namely bacteria, viruses, protozoa, or parasites).(3) Given that many waterborne pathogens are able to survive in aquatic environments for a long time humans are at risk of exposure to the above-mentioned communicable diseases when they use waterways contaminated with fecal matter for drinking, cooking, or bathing purposes.(3)

The lack of access to Improved Sanitation Facilities disproportionately effects the poor urban and rural communities of the world. These effects are pronounced in developing countries such as Sub-Saharan Africa, Southern Asia, and Eastern Africa, where resources for investment in collection and treatment infrastructure are scarce. In contrast, world’s affluent communities face the challenges of maintaining and improving their existing infrastructure, and providing adequate sewage disposal services to new residents in these communities.(6) For instance, Canadian municipalities and communities strive to provide adequate sewage disposal service to its inhabitants. The “Private On-site Sewage Systems”, “Municipal Sanitary Sewer Systems”, or “Served Sewage Haulage” are three pillars of the “Canadian Home Sewage Management Strategy.” Environment Canada’s 2011 Municipal Water Use Report that collected data in 1524 municipalities (accounting for 28.1 of 33.63 million Canadians in 2009), reported that while a large majority of Canadians (87.1%) were served by piped sewer network, about 12.4% used private septic systems(under-reported) and only 0.5% used sewage haulage.(3)

Most urban municipalities (Toronto, Vancouver or St.John’s) are able to provide their residents with traditional engineered sanitary systems, because of their large size and high population densities. (3) Few rural municipalities are competent enough to offer full-range of municipal services to their residents, because the cost of extending municipal services to new dwellings is very expensive. Thus, these residents are increasingly relying on “On-site Sewage Disposal Systems” to treat domestic sewage waste, and “On-site Water Supply” for water.(3) Smaller rural communities have to entirely depend upon these onsite systems because they are simply unable to bear the cost of installing and maintaining municipal services.(3)

Provincial Regulations, Standards and Application Process:

In Newfoundland and Labrador (NL), “for people residing in un-served areas (e.g. municipal sewage service is not available), On-site Sewage Treatment System is often the only practical solution for domestic sewage waste system” (see Appendix C). A septic tank connecting to multiple subsurface absorption trenches is the preferred method of choice over Treatment Moulds, Open Discharge Systems, Sewage Lagoons, Seepage or Leaching Pits, Ocean Outfalls, Pit Privies or Vault Privies, Composting, Incinerating, and Chemical Toilets (Appendix C). The Provincial Government regulates the design, construction and installation of septic systems, under the CNLR 803/96 - Sanitation Regulation under the Health and Community Service Act (Appendix B). “Private Sewage Disposal Systems and Water Supply Standards” outlines the minimum acceptable standards for such conventional systems. Proper location, installation and maintenance, are key for ensuring that a system functions properly for as many years. Each plan must be evaluated to determine if a site meets minimum requirements as specified in the Standard Manual because not every proposed building site can be approved for a “Private Sewage Disposal and Water Supply System.” A Sewage System is not designed to be a decomposing bin or garbage disposal site, and is meant for untreated sewage only.

Before the application process commences, the owner/applicant must have the site thoroughly evaluated by an “Approved Designer (AD)” registered with the local Government Service Centers (GSCs) under Service NL. Certified Public Health Inspectors, Professional Engineers or Certified Engineering Technologists are generally expected to have sufficient expertise to provide proper assessment, designs and construction drawings for proposed systems. Hence, these professionals are automatically considered for “Approved Designer Status” when they apply for registration (See appendix C). In contrast, contractors and other persons who have the necessary technical expertise, but lack appropriate designation, need to successfully write the “Approved Designer Exam” before being registered as AD (Appendix C). The standards state that plans with incomplete information must be returned to the AD for correction and re-submission. Multiple re-submissions, however may lead to suspension of design privileges.

The applicant, or AD acting on behalf of the applicant must submit two complete copies of “Detailed Sewage Disposal Design and Water Supply Design Plan” to the nearby GSC for approval (Appendix C). It is to be noted that Standards state, “No construction or excavation, other than necessary for site evaluation, should commence until a “Certification of Approval” has been issued for a site.” All plans are reviewed and assessed by an Environmental Health Officer (EHO) with Service NL. Once a plan is approved, the “Certification of Approval” is valid for 24 months from the date of issue, with a possibility for further 12-month extension (see Appendix B). A final inspection is required to ensure that the Standards are met under the Sanitary Regulations to protect public health, and to protect all water supplies from pollution. The purpose of this report is to scrutinize the “Final Installation Inspection” of a “Multi-Trench Disposal Sewage System” with a flow rate of less than 4546 liters (L).

Discussion:

File Review and Site Inspection

The “Private Sewage Disposal and Water Supply Plan” was submitted for a privately owned single bedroom cottage located at location in NL, by the applicant’s AD on July 14. Environmental Health Officer Trainee John Doe reviewed the file on July 16, , and submitted his recommendation to the EHO for the approval. The EHO Jane Doe issued “Certificate of Approval” by July 21, The property has a total area of 6,410 Square Meters (m2) /69,000 Square Feet (ft2), with a frontage of 105.16 meter (m) / 345 Feet (ft) and depth of 60.96m/345ft (see Appendix A). In un-serviced areas, a minimum lot size of 1860m2 is required to permit the installation of well and sewage system (see Appendix C). The minimum lot width of 30m is required throughout the entire area in which absorption field is to be installed. This minimum lot width is important, because a site must be able to accommodate the sewage system while maintaining all separation distance and have enough sufficient space for a replacement system. (Appendix C).

On the “Application to Develop Land” Form, the applicant indicates that there are no major farming/livestock operations within 610m (2000ft) radius of the building lot (see Appendix A). This information is disclosed in order to mitigate potential land use conflicts between livestock operations and non-agricultural land uses. For example, surface water or groundwater could become contaminated with fecal matter when a private well is installed too close to a farm/livestock operation. Wells could also be contaminated due to fertilizers, manure, insecticides, and other chemicals used in farm areas located within the recommended parameter.

Moreover, the applicant’s property is not part of any designated watershed in the Province (see Appendix A). In a scenario where the land is part of a designated watershed area, under the Municipalities Act, additional municipal approvals and permits are required to start construction. If a community has no municipal government, the “Department of Environment and Conservation"(NLDLC) is the designate authority on managing watersheds in the province. NLDLC must approve the plan before an EHO starts processing of the application. Communities can have their watersheds designated as a “Protected Public Water Supply Area” under “Section 39 of the Water Resources Act”.(6) This law also protects watersheds from contamination by sewage or other pollutants, by permitting only certain “human activities” in these areas.(2)

The final inspection was conducted on August 15, 2014, by EHOT, under direct supervision of an EHO. At the construction site, EHOT initially checked the applicants file to see if the sewage system was installed according to the approved plan. The Sanitation Regulation state that any major deviation from the approved plan results in rendering the installation invalid, and the installed system automatically fails the final inspection. As a result, “Final Certificate of Approval” is not issued until the system is modified to meet the specified conditions on the “Certificate of Approval”, or plans are revised and submitted for additional scrutiny. In both cases, the final inspection is repeated.

Regarding this submission, a drilled well was to be constructed adjacent to the cottage about 61m (or 200 feet) to the south of the cottage (see Appendix A). The EHOT also measured that separation distance from the drilled well on Property A was 38.8m away from the disposal field and 43.8m from the septic tank. While the drilled well on Property B was 91.44m away from the disposal field and 97.44m for the septic tank. Drilled wells need to be 16m away from both the disposal field and the septic system (see Appendix C). The separation distance from the shed, driveway and property boundaries to the septic tank, or the disposal field, also met the minimum requirements (see appendix A). The minimum separation distances are required to protect underground water sources from sewage contamination.

Residential properties mentioned above are located adjacent to the North and East property boundaries of the site. The Point Road runs parallel with the East property boundary and “Main Road - West Side Road” runs alongside the South (see Appendix A) The separation distance from the “road” to the “absorption trenches” or “septic tank” was more than three meters, which helps reduces or eliminates possibility of nuisance due to sewage leak inside property (see Appendix B). There are no natural watercourses, streams, rivers, ponds, within 30m (100 ft) of property boundaries. The minimum separation distance is required to protect fresh waterways from fecal contamination (see Appendix C). The EHOT measured that the separation distance from septic tank: to the embankment was 3.5m; and to the disposal field was 4.5m as required in the standard (see Appendix A). The embankment stretching along north, east and west side of the septic field. An embankment provides adequate space for lateral movement of effluent to prevent sewage from breakout (see Appendix C). Additionally, surface drainage and roof water must be directed away from the system. Hence, the contractor must allow for finished grade from trench ends to prevent pooling of surface water runoff from entering and saturating the absorption field. (see Appendix C).

Site Evaluation: Soil Suitability and Percolation Test

For site evaluation, the AD had the site excavated for a test pit in the proposed area of disposal field to provide information on Soil Suitability: an estimate of soil permeability using soil classification and other tests), the existence of impervious strata, and the maximum elevation of ground water table. For soil suitability, a minimum of one test hole of depth 1.8m is required to provide information on soil properties such as texture, structure, depth, colour and density (Appendix C). The AD recorded the information from the test pit in the pit log on July 13, 2014. The log shows that soil at the depth of “0m to 0.2m: Topsoil: Dark Brown and Sandy.” At depth of, “0.3m to 1.8 m – Gray Sandy, Gravel: with some 2″ Rocks. No Groundwater or Bedrock observed at 1.8m” (see Appendix A). The Standards require a minimum amount of soil cover to treat wastewater. The presence of impervious strata impedes proper wastewater treatment or allows wastewater to escape via fissures and contaminate the underground water table (see Appendix C).
Additionally, the AD did not report any signs of mottling during the soil evaluation. Mottles are spots or streaks of different colour, mostly grey and red, which result from chemical and biochemical reactions when saturated conditions, organic matter, and temperatures above 4oC occur together in the soil (see Appendix C). Mottling indicates periodic soil saturation, during wet seasons, but it does not always indicate lack of saturation. The land has very gentle 1% slope, going in northerly direction. This slope meets minimum requirements, as lots with slopes in excess of 30% are unacceptable for “Conventional On-Site Sewage Treatment Systems”, because they present high-risk sewage effluent breakout (Appendix C). The standard also recommends installing an absorption field across a slope to prevent further breakout.

Since good soils make good systems, only certain soils are acceptable for the effective absorption and treatment of sewage effluent. Soils acceptable for the effective absorption and treatment of sewage have percolation rates of less than 30minute/2.5cm (or 30min/inch), and soils with percolation rate greater than 60min/inch are not considered for conventional designs (see Appendix C). The information regarding soil strata and type can be described with reference to texture, colour, porosity and consistency of soil. In the standards, three acceptable soils for on-site Sub-sewage system are, “Sands and Gravels” which are not widely available in the Province exhibits percolation rate of less than 5min/inch. “Loams” are a mixture of sand, silt, and gravel, which provide the most effective permeability and treatment of effluent, and exhibits percolation rates less than 15min/inch. “Silts”, which are beige or tar color often with evidence of mottling, has percolation rates from 15min/inch (for dry silt with high sand content) to in excess of 30 min/inch for (harder silts) (Appendix C). The Ribbon Test (squeezing a moistened ball of soil out between thumb and fingers) or Moist Cast Test (compress some moist soil by clenching it in your hand) are done to help determine the soil’s texture. The soils with coarser granules have casts that are smaller in length and more fragile (Appendix C).

To conduct a percolation test, three holes at a maximum depth of 91cm were dug to test the soils capacity to absorb water (see Appendix B). Percolation tests are conducted by measuring the time it takes for water to drop one-inch in saturated soil. The AD calculated the percolation rate was 6 min/inch (Appendix A). By itself, percolation tests are not an adequate determinant of soil quality, because under favorable climatic conditions (like in a dry spring) one could obtain favorable rates. Hence, to improve reliability of the percolation tests, the soil strata information must be referenced to identify key markers present in the soil to make data-logs more reliable (see Appendix C).

The Septic Tank: Function, Design and Inspection.

The “standard” septic tank is composed of a single or a double compartment tank, which provides primary treatment of effluent by separating solids from the domestic sewage waste. The lighter solids float to the top, while the sludge settles to the bottom. This separation leaves relatively clear effluent in-between the two layers. Anaerobic conditions inside a septic tank encourage “Anaerobic Bacterial Activity” (bacterial activity in anaerobic condition by anaerobic and facultative bacteria), which partially breaks down the waste in the septic system. Anaerobic digestion results in production of landfill gas (mainly carbon dioxide, methane, and hydrogen sulphide) that collect at top scum layer. As a warning, no one should attempt entering a septic tank, and one must be careful when looking into a septic tank since inhalation of toxic gases present inside the tank could be fatal for humans (see Appendix C). The effluent that leaves the tank for secondary treatment should be ideally free of suspended fats, grease, and other solids.

The Septic tank is the workhorse of the septic system, and plays a crucial role in not only preventing sludge and scum from entering the disposal field, but also removing 40% to 50% of the 5-day biochemical oxygen demand; 50 to 70% of the total suspended solids; and up to 20 to 30% phosphate (Appendix C). Furthermore, pathogens do not multiply in the septic tank. As a result, the numbers of the surviving bacteria in the effluent are severely reduced, alongside organic materials, and many viruses (Appendix C). Given that the scum and sludge layer is always growing, a septic tank should be pumped out regularly (for instance, every three years) to prevent septic tank clogging. This helps maintain optimum efficiency of the sewage system. A professional contractor should be contracted to regularly inspect the septic tank for the client.

For a one-bedroom-cottage, a septic tank of minimum liquid capacity of 2,300 liters (or 500 gallons) was deemed satisfactory to meet requirements for the dwelling. The Standards state that size of the septic tank size for a residential dwelling should be determined on the bases of the number of bedrooms. The EHOT noted that contractor had installed concrete watertight CSA approved septic tank. These tanks have space equalling 20% of its liquid depth reserved to accommodate the gases being released by the anaerobic decomposition of the wastewater. The inlet and outlet of the tank were 10 cm in diameter, and the crown of the outlet was 5cm below the crown of the inlet. It had an open top inlet tee or baffle extending 15cm above and 30cm below the liquid level, the open top outlet tee or baffle was extending 15cm above and 41cm below the liquid level. The pipes were angled gently to prevent them from resting against the baffles and retarding flows. The septic tank had a manhole (roofed with a concrete cover) adjacent to the cottage, and had the smaller opening (covered) towards the distribution box (see Appendix B). The Building Sewer was attached to inlet of the septic tank with a solid 4-inch (or 10 cm) CSA approved pipe. The line from outlet of septic tank attaches to the inlet of the distribution box (see Appendix A).

During the inspection, the distance from the cottage to the septic system was one-meter (or three-feet), and the grade of the house sewer (measured using a leveling scale) was greater than one-centimeter per meter (or 1/8 inch per foot). The minimum grade is important, since it will allow uninterrupted sewage flow from the house to the septic tank. The lack of grade could cause the sewage (especially the solids) to build in the sewer that can clog the pipe. The pressure in the pipe then builds up against the clog in the house sewer, causing pipe to rupture and contaminate the area with sewage. Alternatively, if slope is reversed, it could cause the sewage back flow from the building sewer into the toilet, causing system malfunction, and causing sewage to flood the cottage. Hence, if an EHO detects such breach of standards, the system fails the inspection, until the contractor ratifies the situation (see Appendix C).

The EHOT noted that the septic tank was installed correctly (by checking if the crown of the outlet was below the crown of the inlet). The EHOT noted that the septic tank was level, which is crucial for sewage to settle properly. If a septic tank is uneven, then it can result in excessive amounts of solid effluent to leave the tank, and enter the absorption field. Overtime, this will reduce the overall efficiency of the sewage system, as absorption field will become clogged and eventually the whole sewage system to malfunction (Appendix C). Additionally, the minimum grade of 1/8 inch per foot from tank to distribution box was met. This grade is necessary to prevent effluent from pooling in the piping between the septic system and the building sewer (Appendix C). A minimum grade is recommended to help attain steady rate of flow, which helps maintain the overall efficiency of the entire septic system

Distribution Box: Function, Design and Inspection.

In a septic system, the distribution box and the absorption trenches form the absorption field. The effluent from the dwelling flows from the septic tank through the different outlets in the distribution box to each absorption trench. The outlets must be level with each other for each line to receive equal volume of effluent. If outlet pipes are not level, the balance of the system will be skewed, and this will accelerate the wear and tear of the system, and overtime make the sewage system less efficient, as uneven flow will overuse on one portion of the system which will result in malfunction such as ponding of effluent on surface (see Appendix C).

For the system, the contractor installed a watertight concrete distribution box to prevent surface water infiltration. The standards recommend having gravel fill or footing below the box, extending below frost, to keep the box level. It has a removable concrete cover that fits over the box. It has inlets and outlets equipped with flanges to accept pipe work, and provide easily sealable joints. It has outlets that are flush with interior walls of the box. All of the outlets are at same level with each other; the crown of the inlet is designed to be 5cm higher than the crown of the outlets to prevent wastewater from back flowing into the septic tank and causing a system malfunction (see Appendix C). All the outlets and the inlet are designed to accept 4-inch diameter pipe. In the box, a minimum spacing of 10 cm is maintained between outlets pipes to protect the integrity of the distribution box. The box is attached to the solid sewer line (10cm in diameter) from the septic tank, and three solid outlet pipes are attached to the perforated 4-inch ridged pipe in each absorption trenches. Pipes are attached to sealing joints in the inlet and outlets to prevent soil/groundwater contamination (see Appendix C).
While the unused outlets were caped, the other three outlets and the inlet have their joints sealed with watertight seals (composed of PVC). After using a leveling scale to see if the distribution box was level, the EHOT used the bucket of water provided at the site to fill the distribution box to reasonable depth. The EHOT observed water level decrease and the water was evenly distributed into the three outlets. The EHOT concluded that the distribution box was level, and all three outlets discharged equal amount effluent into their absorption trench, which is satisfactory.

Absorption Trenches: Function, Design and Inspection

After leaving the distribution box, the effluent enters the absorption trenches. These are series of perforated pipes laid in a bed of crushed stones, which filter and distribute the effluent through the field by allowing the effluent to slowly trickle into the stone and then into the soil. Gravel or crushed rock provides storage for peak effluent flows. A large infiltration surface between the effluent and the underlining soil or sand, provides a bed for the pipe and protection over it (see Appendix C). Overtime the continuous or frequent ponding of septic tank effluent, on the bottom of the absorption field results in growth of a biological layer that increasingly filters out solids particles and dissolved pollutants from the effluent. A “Clogging Mat extends by 0.5 to 6cm into the soil, and consists of slimy mass of septic tank effluent solids, minerals precipitates, microorganisms, and by-products of decomposition (see Appendix C).
Microorganism in the mat feed on septic tank effluent nutrients to produce slimes, polysaccharides, carbon dioxide and other by-products of decomposition, hydrolyzation and bio-degradation process(see Appendix C). As the effluent filters through the soil, organisms present in the soil act to remove harmful bacteria, viruses, and other pollutants. For example, within the absorption trench, at a depth of about foot or beyond of the clogging mat: 1). Total Coliform Concentration of 57,000 CFU/ml is typically reduced to less than 200 CFU/ml. 2). Fecal Coliform Concentration of 19000-CFU/ml is reduced to less than 2-CFU/ml; and, 3). Fecal Streptococci Concentration of 1600 CFU/ml is reduced to 2-CFU/ml (Appendix C). The clogging mat typically removes approximately 10% of the nitrogen, but is less effective in removing phosphates (Appendix C). Unlike the septic tank, treatment in absorption fields is facilitated through the activity of aerobic bacteria. Since oxygen levels diminish with increase in depth of soil; it is important that the depth of absorption trench does not exceed the maximum depth (91cm) set out in the Standards. Trenches deeper than 91cm increase the likelihood of the system to malfunction (Appendix C).

The soil on the cottage lot had a percolation rate of six-min per inch. Thus, the cottage was approved for minimum trench size of 45m. The percolation rate and the proposed number of bedrooms determine the total size of the absorption trenches for residential dwellings. (Appendix C) The system was approved for three-absorption trenches of 15m. The trenches in a sewage system are limited to length of 30m. It is impractical for mechanical system to transport effluent to greater distances, without help of a pump, which could cause the effluent to fail to reach entire length and can cause the system to overload and malfunction. The separation distance between the cottage and disposal field was 6m, which was satisfactory (see Appendix C).

Additionally, the applicant was advised to seed or sod the disposal field soon after the system was installed to ensure the system to receive the full benefits from “transpiration”. “Evapotranspiration” is the uptake of moisture through “Evaporation”, and through “transportation” by the roots of vegetation, and contributes to the effective functioning of the disposal field by reducing absorption load on the soil (Appendix C). When the septic disposal fields are of recommended depths of 61-91cm, it increases evaporation rate in the field, which increases the transpiration rate. During the inspection, the EHOT used the measuring tape and confirmed the trenches were at least 15m, and that the ends of the lines were capped, to prevent effluent pooling on the ends of the trenches and spreading to areas not designed to treat effluent (Appendix C).

The piping from the distribution connecting to the three trenches were 10cm CSA approved solid lines, and the pipes in the trenches were 10cm CSA approved perforated pipes. The leveling scale was used to ensure that the grade in the trench lines did not exceed “5cm per 15m.” The trench width was adequately spaced at 52cm (the standard spacing is 46–61cm) which meets the Standards (Appendix C). If the trenches are too narrow they will not allow for proper pipe installation, and if the trenches are overly wide, they are unnecessarily costly. The trench depth was adequate and between 61-91cm (Appendix C).

The EHOT noticed, that the size of crush stone was average around 3-4 cm between standard range of 1.9-6cm. If the crushed stone are too big or too small, they do not allow the effluent to distribute evenly in the absorption field, which cause malfunctioning of the system. The trenches had 3-4 inches of crushed stone cover over then, which met the standard. The stone in the trenches were covered with an untreated building paper, to prevent clogging but not inhibiting evapotranspiration (Appendix C). Since the requirements for a “Back Fill Inspection – Checklist Form” (see Appendix A) were met or exceeded expectations, the EHOT filled out the form and recommended to the EHO to issue the “Final Certification of Approval.” The EHOT informed the Designer of the “Back-Fill Inspection Approval” and gave the contractor permission to cover the system. The “Final Approval Certificate”, was issued to the applicant with instructions to ensure that minimum amount of fats and grease in a household kitchen, going into the system; by inspecting grease traps and cleaning them regularly. Lastly, on the use of Water Treatment Units, EHOT advised the applicant not to discharge the backwash water in to the sewage disposal system, to prevent septic systems to malfunction (Appendix C).

Conclusion:

Potable water contaminated with untreated sewage poses serious health risks to humans. If proper precautions are taken, such contamination can easily be prevented and a number of waterborne diseases can be also prevented. In Newfoundland and Labrador, for people residing in un-served areas, on-site sewage treatment is often the only practical solution for domestic sewage waste system. “Multiple subsurface absorption trenches” is preferred method of On-site Sewage Disposal System. EHOs enforce the “Sanitation Regulation” and “Private Sewage Disposal and Water Supply Standards” for installation of “Private Sewage Disposal and Water Supply Systems”. Each plan must be evaluated to determine if a site meets minimum requirements as specified in the Standard Manual because not every proposed building site can be approved for a “Private Sewage Disposal and Water Supply System”. The Final inspection is important to ensure that the system is installed according to approved plan and meet the Standards to protect public health, and to protect groundwater and waterways from sewage contamination.

An Approved Designer submits the sewage system plan to Service NL for review by an Environmental Health Officer (EHO). If deemed satisfactory the “Certification of Approval” is issued to the applicant. It is crucial that the building lot where the sewage system is proposed has a sufficient size to allow the appropriate separation distances between wells, springs, existing building, inland waters, property boundaries, and embankments along with sufficient space to accommodate a complete replacement system. For effective functioning of a sewage system, the percolation rate of the site soil must meet the accepted standards. The slope of the land should not exceed 30% to prevent sewage affluent breakout. A septic tank forms an important component of all “Private Sewage Disposal Systems” and all household effluent must be discharged into septic tank. The septic tank installed must be “Canadian Standards Association” (CSA) approved, to prevent leakages, blockages, and backflow of sewage. For effective absorption, the “Distribution Box” must be level to distribute wastewater equally to all outlets. The total size of “Absorption Trenches” for residential dwellings should be constructed according the percolation rate of the soil and the number of bedrooms, to prevent overloading of the system. The surface drainage and roof water must be directed away from the system to prevent water from other sources entering and saturating the absorption field.

Hence, sewage systems can provide many years of unproblematic service, if they are designed, installed, attended, and maintained properly. However, overloading a system or failure to clean out the septic tank on regular basis can cause many problems. Thus, to help improve efficiency of sewage disposal systems, they must be used for sewage treatment only, because they are not designed as decomposing bins, garbage container, or chemical waste disposal site. The area above a disposal field should have good grass cover, but planting of trees or shrubs is not recommended because they might plug the system, or lessens the evapo-transpiration.
Hence, well-maintained sewage systems protect the groundwater from sewage contamination for years to come, by efficiently treating wastewater of harmful pathogens, and other physical and chemical contaminants. Thus, by protecting the groundwater and other waterways, sewage systems play a crucial role in protecting the health of public, by preventing outbreaks of waterborne communicable illnesses in the community.

References: 1. Blacksmith Institute in collaboration with Green Cross Switzerland. "WORST POLLUTION PROBLEMS: THE WORLD’S WORST POLLUTION PROBLEMS: THE TOP TEN OF THE TOXIC TWENTY." 2008. WorstPolluted.org: Reports. Last accessed on: January 16, 2014. Available at: http://www.worstpolluted.org/reports/file/World%27s%20Worst%20Pollution%20Problems%202008.pdf 2. Department of Environment and Conservation: Protected Water Supply Areas (2015). Last accessed on: January 16, 2014. Available at: http://www.env.gov.nl.ca/env/waterres/quality/drinkingwater/protectedareas.html 3. Environment Canada: Municipal Water Use Report: Municipal Water Use 2009 Statistics (2011). Ministry of Environment. Last accessed on: January 16, 2014. Available at: http://ec.gc.ca/Publications/default.asp?lang=En&xml=B77CE4D0-80D4-4FEB-AFFA-0201BE6FB37B 4. Pruss-Ustun A, Bos R, Gore F, Bartram J. 2008. “Safer water, better health: costs, benefits and sustainability of interventions to protect and promote health”. Geneva: World Health Organization. Last accessed on: January 16, 2014. Available at: http://www.who.int/quantifying_ehimpacts/publications/saferwater/en/index.html 5. SNL1999 CHAPTER M-24: Municipalities Act (1999). Last accessed on: January 16, 2014. Available at: http://www.assembly.nl.ca/Legislation/sr/statutes/m24.htm 6. UN World Water Development Report 2: “Water: A Shared Responsibility (2006). United Nation Educational, Scientific and Cultural Organization. Last Accessed On: January 16, 2014: Last accessed on: January 16, 2014. Available at: http://ww2.unhabitat.org/programmes/water/documents/waterreport2.pdf 7. World Health Organization (WHO). 2008. “2.4 billion people will lack improved sanitation in 2015.” Last accessed on: January 16, 2014. Available at: http://www.who.int/mediacentre/news/notes/2013/sanitation_mdg_20130513/en/

Additional Resources: A. British Columbia Government: ESTIMATING SOILTEXTURE IN THE FIELD. Last accessed on: January 16, 2014. Available at: http://www.for.gov.bc.ca/isb/forms/lib/FS238.PDF B. Colorado Master Garden Notes #214: Estimating Soil Texture: Sandy, Loamy or Clayey? Colorado Master Garden Program, Colorado State University. Last accessed on: January 16, 2014. Available at: http://www.ext.colostate.edu/mg/gardennotes/214.pdf C. Fewtrell L, Kaufmann RB, Kay D, Enanoria W, Haller L, Colford JM Jr. 2005. Water, sanitation, and hygiene interventions to reduce diarrhoea in less developed countries: a systematic review and metaanalysis. The Lancet Infectious Diseases, 5(1):42–52. Last accessed on: January 16, 2014. Available at: http://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0CCcQFjAB&url=http%3A%2F%2Fsiteresources.worldbank.org%2FHEALTHNUTRITIONANDPOPULATION%2FResources%2F281627-1095698140167%2FFewtrell%26ColfordJuly2004.pdf&ei=GIXHVIeLIsqXNpS_g4AM&usg=AFQjCNHu4i9JEPlQ8DJbVpBwk_suZYx8kw&bvm=bv.84349003,d.eXY D. Health Canada (2013). Guidance on waterborne bacterial pathogens. Water, Air and Climate Change Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario (Catalogue No. H129-25/1-2014E-PDF). Last accessed on: January 16, 2014. Available at: http://www.hc-sc.gc.ca/ewh-semt/pubs/water-eau/pathogens-pathogenes/index-eng.php E. Report on the Environment: Highlight of National Trends (2008). United States Environmental Protection Agency (2008). Last accessed on: January 16, 2014. Available at: http://www.epa.gov/roe/docs/roe_hd/ROE_HD_Final_2008.pdf F. SNL2002 CHAPTER W-4.01 - WATER RESOURCES ACT(2002). Last accessed on: January 16, 2014. Available at: http://assembly.nl.ca/legislation/sr/statutes/w04-01.htm G. World Health Organization (WHO). 2008. “International Year of Sanitation 2008” Last accessed on: January 16, 2014. Available at:
http://www.who.int/water_sanitation_health/hygiene/iys/about/en/index.html