Septics systems are a dirty business...well, at least if you need it replaced! Starting from a new installation makes for a much easier (and cleaner job). A septic system is both simple and complex. It is composed of a holding tank, a distribution box, and perforated drain lines that exit into a leech field. Thats really where the simplicity ends. Provincial guidelines from Service NL (http://www.servicenl.gov.nl.ca/publications/private_sewage_disposal_and_water_supply_standards.pdf) provide a prescriptive approach to designing a septic field. The design depends on many parameters e.g. number of bedrooms, type of soil, percolation tests, separation from residential water sources, etc. It is not something that you can do yourself! It requires the knowledge of an approved septic designer that is licensed to practice. In this case the company I have used for excavation, Wade's Excavation and Septic Services, not only provides the design but also does the installation. In this particular case, since the septic field is not accessible from the main entry to the property, we decided to go with a fibreglass septic tank. Some benefits include easy handling, no metal components that can rust, less degradation over time when compared to a pre-cast concrete tank.
Living in a rural area often means there is no access to sewerage services so a traditional septic system is really the only option...well, this is not completely true. There are some mechanically aerated systems on the market which work really well and are great if you want/need to minimize the foot print of the leech field. In fact, those systems require a leech field that is about 75% smaller than a traditional septic field and the effluent that exits them is often completely clear and doesnt even carry odour. Those systems were outside my budget for this house so our only option was a traditional septic field. Septic fields can cause trouble if not cared for. Following some simple rules will ensure that the system remains in use for many years to come. Since a septic system requires the action of anaerobic organisms to break down solid matter, shocking the system with chemicals like bleach is not a good idea. Using cleaners that indicate they are safe for septic systems are a good idea. Septic fields are good for breaking down digested solid waste. The introduction of additional solid waste, like tissues and other personal hygiene products, can lead to premature failure of the system so its best to find products that are rated for septic tanks. Even if those products cost a little more, they won't cost as much as replacing a clogged septic system. Solid food waste should be confined to a garbage and my understanding is that garburators shouldn't be used. Although the pieces of food are chopped up small, a septic doesn't digest food! A garburator does exist that uses enzymatic action to break down food and liquify it (https://www.insinkerator.com/us/en/evolution-septic-assist-garbage-disposal). Another, less costly, option is to just use the strainer in the sink and throw scraps in the garbage.
As mapped out in the provincial standards, our system is composed of a tank, and a distribution box as can be seen in Photo 1-1 and 1-2. By the end of the day, the leech field trenches were dug and 4x50' lines (sized for our household) were installed in a stone bed. The lines were covered with more stone and landscape fabric. The system is now awaiting provincial inspection. Inspection typically takes about 1 week from time of inspection request. At this point its another part of the puzzle completed, a little more than a month after the footings were poured. I am overly pleased with how planning has worked out on this project. Although its been cold (i.e. averaging about 3-4 C cooler than most years), it has been dry. June is mostly filled with rain, drizzle and fog. This year has been a pleasant surprise and has given us a great start on the Flatrock passive house.
Photo 1-1. Septic Tank and drain line entering into the distribution box.
Photo 1-2. Four lines exit the distribution box.
Photo 1-3. Septic leach field, seepage lines installed. The trenches are filled with drainage stone and covered with landscape fabric.