Practitioner's Tool / Barangay Rapid Technical Assessment
Rapid Technical Assessment Rapid technical assessments are used to review existing technologies to determine what is working and what could be working better as well as to develop marketable solutions to make on-site wastewater systems easier to purchase, install, use and maintain. In San Fernando, La Union, Philippines, teams of Barangay health workers and licensed plumbers performed a rapid technical assessment of 125 homes in 2 days. The entire force of health workers used the information gathered from the assessment in campaigns to promote their program. The following is adapted from their training manual:
Performing Rapid Technical Assessments
- Step 1: Gather baseline data and document existing conditions
- Step 2: Assess the septic tank or latrine
- Step 3: Identify any plumbing problems in the building
Step 1: Baseline Data
In this step, the team gathers the baseline data and documents existing conditions. This generally starts with the team touring the house and property accompanied by the building owner or occupant. As the team walks around, they look for key sanitation components: toilets, septic tanks, drainage lines and others. After the brief tour, the plumber and engineer work together to document the existing conditions by preparing a site plan sketch. At the same time, the health worker sits down with the owner or occupant and conducts a survey about his or her knowledge, attitudes and practices regarding sanitation. The end result is a completed site plan sketch and valuable survey data.
Site Plan Checklist
- North arrow shown
- Nearest street or road shown
- Property lines shown
- Parking area shown
- All buildings and paved areas shown
- Location of well, water line shown
- Location of existing septic tank, pit toilet, other sanitary structures shown
- Greywater discharge point shown
- Sewer line from house to septic tank, septic tank to sewer shown
- Topography: arrows that indicate the slope shown
Questions to consider as you make the site plan sketch
1. Is this property in a floodplain?
- Yes. If so, how often does it flood, and how high does the flood water get?
2. Are buildings from neighboring properties connected to the septic tank?
- Yes. If so, be sure to draw them along with the sewer lines
3. Are roof gutters and surface drainage directed away from the septic tank?
4. Is there any land on the property available for a new septic tank, pit toilet, and/or on-site irrigation?
- Yes. If so, identify it on the site plan.
5. Where does the wastewater go after it leaves the house/septic tank?
- All underground – it leaches from the septic tank
- Effluent or sewage flows through a closed pipe or channel to off-site drainage
- Effluent or sewage flows through an open channel to off site drainage
Click here for more information on creating a site plan sketch.
In this step, also determine where the latrine or septic tank is on the property, if there is an access port over each septic tank compartment and the accessibility of the septic tank or latrine for desludging. Septic tanks are often located in the home, either somewhere under the comfort room or under the kitchen. Sometimes, homeowners can help identify openings in the floor that may lead to septic tanks.
Hint - If you cannot locate the tank, try the tic tic method of using a steel bar to gently tap on the floor to locate the septic tank. Hollow sounds when tapping may indicate the location of the tank.
Step 2: Evaluate the Septic Tank
Safety tips for septic tanks:
- Never enter a septic tank. Septic tanks are confined spaces that can accumulate toxic gasses and displace oxygen. Workers entering a tank can be quickly overcome. Only licensed septic tank desludgers should clean septic tanks.
- Never smoke around a septic tank. Septic tanks produce biogas containing methane, which is explosive and can be ignited by cigarettes or lighters.
- Wash your hands. Always wash your hands after coming in contact with septic tanks, wastewater or sewage. Sewage contains bacteria and other pathogens that can make you sick, and you can pass on disease-causing germs to your family. Protect yourself by washing your hands often.
- Secure septic tank access ports. Access ports must be protected from unauthorized entry. Children especially are at risk of falling into or otherwise entering unsecured septic tanks. Secure lids with safety screws or other devices to keep kids out.
Checking the septic tank
- Locate the septic tank; it may be under the building. Look for cleanout or access ports in the bathroom or kitchen.
- Determine if the manhole or risers can be opened. Sometimes these are cemented shut or otherwise inaccessible. Septic tanks will need functional access ports for desludging and inspection. Note, all tank lids should be locked to keep kids out!
- Try to determine if the septic tank has a drainage pipe, or if it is a leaching septic tank with discharge out of the bottom of the tank. Ask the owner as he or she may have knowledge of the installation. If it does have a discharge pipe, try to locate it.
- Check the water level in the septic tank. If low (below flow level of outlet pipe), the septic tank may be leaking. If high (above the flow level of the outlet pipe), the outlet could be clogged.
- If your septic tank inspection coincides with desludging, check the soundness of the concrete, looking for obvious cracks or corrosion. Check the inlet and outlet pipes to make sure they are present and in good condition.
Step 3: Evaluate the Plumbing and Venting
Often, bad plumbing or poor venting can cause odors in the home, excessive water use, and drainage problems. Check the toilets for sound installation. Look for P-traps (curved pipesused in drains, pictured below) and listen for water leaks (does the toilet run?). Finally, check the roof. Proper venting of septic tanks is through the plumbing stack in the building.
Hint - Vent pipes protruding through the roof are a good indication of proper venting. Lack of vent pipes indicates potential venting problems. Hint - Venting at the roof level is proper. Venting septic tanks at street level can lead to odors in communities.
A house plumbing system is called a DWV system for Drain/Wastewater/Ventilation. Over each drain there must also be a riser--a length of pipe that connects the drain plumbing to a vent above the roof, permitting gas to escape. You can distinguish a DWV vent from other roof perforations because they are open on top, as rain coming in does not affect the drain pipes.
Being gasses, noxious vapors will vent where they can. So to ensure that gasses stay inside the system and go to the roof, plumbers install a P-trap at all drains, except under your toilet, whose bowl itself serves as a trap.
The trap is very simple. Imagine a capital "P" turned on its side so the fat part points down. As you run water through the sink, wastewater will flow down into the "P" and back up down the stem into the DWV riser. When you shut off the sink, a small amount of water remains trapped in the "P," blocking the gasses. The water does not get rancid because you change it every time you run the faucet.