Waste Systems & Fire Safety

Alternative Waste Systems

• OSST (On-site sewage treatment) systems typically include a building sewer leading to a septic tank, then a distribution box, and finally a drainage field. These systems are designed to treat and dispose of wastewater on-site, making them suitable for areas without access to centralized sewer systems. Regular maintenance, including periodic inspections and pumping, is essential to ensure the proper functioning and longevity of OSST systems.

• Wastewater (sewage): "Used" water containing waste products. Wastewater treatment is a multi-stage process that removes contaminants and pollutants from wastewater to make it safe for discharge back into the environment or for reuse.

• Gray water: Wastewater from washing processes (e.g., showers, sinks). Gray water can be recycled for non-potable uses such as irrigation and toilet flushing, reducing the demand for fresh water resources.

• Black water: Wastewater containing fecal matter and urine (e.g., toilets). Black water requires more intensive treatment than gray water due to the presence of pathogens and high levels of organic matter.

• Effluent: Water discharged from a private sewage disposal system. Effluent quality is regulated to protect water resources and public health. Regular testing of effluent is often required to ensure compliance with regulatory standards.

• Baffle: Inlet and outlet sanitary tees in a septic tank. Baffles prevent solids from entering the drainage field and help to maintain a consistent flow of wastewater through the tank, which improves the treatment process.

• Sludge: Solid waste settled in wastewater treatment. Sludge is typically treated to reduce its volume and pathogen content before being disposed of or reused as fertilizer.

• Scum: Floating materials like grease and oil. Scum accumulation can interfere with the treatment process and needs to be periodically removed from the septic tank to maintain its efficiency.

Septic Tank

• A watertight receptacle that receives discharge from a sanitary plumbing system. Septic tanks are typically made of concrete, fiberglass, or plastic and must be watertight to prevent groundwater contamination. Proper sizing of the septic tank is essential to ensure adequate treatment of wastewater.

• Retains solids and digests organic matter. The anaerobic digestion of organic matter in the septic tank reduces the volume of solids and produces biogas, which is vented to the atmosphere.

• Liquids discharge into the soil through subsurface piping or seepage pit. The soil acts as a natural filter, removing additional contaminants from the wastewater before it reaches groundwater.

• Plans for septic tanks must be submitted for approval, showing dimensions and structural details. Approval ensures that the septic tank meets regulatory standards and is properly designed for the intended site conditions.

• Design should produce clarified effluent and provide space for sludge and scum. Proper design can optimize the settling of solids and the digestion of organic matter, leading to improved effluent quality.

• Materials must be durable, corrosion-resistant, and watertight. Materials selection is critical to ensure the long-term performance and reliability of the septic tank.

• Minimum of two compartments is required. The two-compartment design enhances the settling of solids and reduces the carryover of solids into the drainage field.

• Inlet compartment: $2/3$ of total capacity, minimum 2 cu.m. The larger inlet compartment provides ample space for the initial settling of solids.

• Secondary compartment: Minimum 1 cu.m, maximum $1/3$ of total capacity. The secondary compartment provides additional settling and treatment of wastewater.

• Two manholes (508 mm minimum) or a removable cover slab are needed for access. Access is needed for inspection, maintenance, and pumping of the septic tank.

• Inlet and outlet pipe openings should be no smaller than the connecting sewer pipe. Proper sizing of the inlet and outlet pipes prevents blockages and ensures smooth flow of wastewater through the tank.

• The inlet and outlet pipe or baffle should extend 101.6 mm above and at least 304.8 mm below the water surface. This design prevents short-circuiting of wastewater and ensures that solids and scum are retained in the tank.

• Sidewalls should extend at least 228.6 mm above the liquid depth. Adequate sidewall height prevents wastewater from overflowing during periods of high flow.

• Septic tank covers must support an earth load of at least 14.4 kPa. Structural integrity of the cover is essential to prevent collapse and ensure safety.

Effluent Disposal

• Subsurface disposal fields: These are designed to distribute effluent evenly over a soil area for further treatment.

• One or more seepage pits: Used where soil conditions are suitable for effluent absorption.

• Combination of subsurface disposal field and seepage pits: This provides flexibility in effluent disposal based on site conditions and wastewater volume.

Disposal Fields

• Also known as leach fields or leach drains, remove contaminants from septic tank effluent. They consist of trenches filled with gravel or other porous media, with perforated pipes that distribute the effluent. Soil properties, such as permeability and depth to groundwater, are critical factors in the design of disposal fields.

Seepage Pits

• Covered pit with open-jointed lining for effluent seepage into the soil. Seepage pits are typically used in areas with well-drained soils and a deep water table. The pit should be sized to accommodate the expected daily wastewater flow, and the surrounding soil should be tested for its ability to absorb the effluent.

Minimum Horizontal Distance Requirements

• Building/Structure: Septic Tank (1.5 m), Disposal Field (2.4 m), Seepage Pit (2.4 m)

• Water Supply Wells: Septic Tank (15.2 m), Disposal Field (30.5 m), Seepage Pit (45.7 m)

• Streams: 15.2 m for Septic Tank and Disposal Field, 30.5 m for Seepage Pit

Septic Tank Capacity

• Based on number of bedrooms or drainage fixture units (DFU). Septic tank capacity should be sufficient to handle the expected daily wastewater flow. Undersized septic tanks can lead to system failure and groundwater contamination.

• Example: 1-2 bedrooms require a minimum of 2838.00 liters.

Septic Tank Design

• Determine the use of the structure to select the appropriate table in the code. Building codes typically provide tables that specify minimum septic tank capacity based on the type and size of the building.

• Select the applicable table and determine the minimum septic tank capacity.

• Set the width and height based on planning restrictions. Local regulations may impose restrictions on the size and location of septic tanks.

• Determine the length by dividing the minimum septic tank capacity by the width and height.

• Apply the ratio ($2/3$ and $1/3$) to the length to determine the length of the two chambers.

• Apply standards for inlet and outlet pipes, manholes, and sidewalls.

Life Safety Systems

• Systems protecting human life during emergencies, including fire-resistant materials, sprinklers, and alarms. These systems are designed to detect, suppress, and contain fires, as well as provide safe evacuation routes for building occupants.

• Fire requires oxygen, heat, and fuel.

Fire Progression

1. Ignition

2. Flame Spread

3. Flashover

4. Consumption

Passive Fire Protection

• Constructing walls, floors, and ceilings to resist and contain fire. Passive fire protection measures are built into the structure of the building and do not require activation to be effective. They rely on fire-resistant materials and construction techniques to slow the spread of fire and provide time for evacuation.

• Providing structural and thermal integrity during a fire.

• Compartmentalizing spaces to control fire spread.

• Providing safe evacuation routes.

• Structural Fire Protection: Guards structural components.

• Compartmentation: Fire barriers, firewalls, fire partitions, and smoke barriers.

• Opening Protection: Fire doors and windows.

Active Fire Protection

• Systems like standpipe, sprinkler, and spray systems to extinguish or control fire. Active fire protection systems require activation to be effective and are designed to suppress or extinguish fires in their early stages. These systems may use water, foam, or other extinguishing agents.

• Firefighting media: water, foams, inert gases, and chemical powders.
  

*Water-Based System: These systems use water as the primary extinguishing agent and are effective for many types of fires.

*Hydrant System: Provides a ready source of water for firefighters to use in extinguishing fires. Hydrant systems are typically located outside of buildings and are connected to a municipal water supply.

*Wet Riser System: A type of standpipe system that is filled with water at all times and is ready for immediate use by firefighters.

*Automatic Sprinkler System: A network of pipes and sprinkler heads that automatically release water when a fire is detected. Sprinkler systems are one of the most effective fire suppression systems available.

Fire Resistance Ratings

• Measure of fire endurance in hours or minutes. Fire resistance ratings are determined by standardized testing procedures and indicate how long a material or assembly can withstand exposure to fire before failing structurally or allowing fire to spread.

• Concrete: Excellent fire-resistant material.
  

*RC structures can resist fire for about 1 hour at 1000 degrees.

• Stucco: Excellent and durable fire-resistant finish.
  

*Gypsum: Resists fire due to water content.

• Bricks: Can withstand very high temperatures (1200-1300 degrees Celsius).

Properties of Fire-Resistant Materials

• Should not expand under heat.

• Should not disintegrate under heat.

• Should not lose strength when subjected to fire.

• Should not catch fire easily.

Flame-Spread Ratings (FSR)

• Measures surface-burning characteristics of a material. Flame-spread ratings indicate how quickly a flame will spread across the surface of a material. Lower FSR values indicate better fire resistance.

• Class A (FSR 0–25): Very low flame spread (e.g., concrete, gypsum board).

• Class B (FSR 26–75): Moderate flame spread (e.g., fire-treated wood).

• Class C (FSR 76–200): High flame spread (e.g., untreated wood).

• Materials with an FSR greater than 200 are typically not approved for interior use due to high flammability.

Fire Extinguisher Types:

• Class A: Combustible materials.

• Class B: Flammable liquids.

• Class C: Flammable gases.

• Class D: Flammable metals.

• Class F: Deep fat fryers.
  

*Extinguisher Types:

*Water: Effective for Class A fires.

*Foam: Effective for Class A and Class B fires.

*Dry Powder: Effective for Class A, Class B, and Class C fires.

*Wet Chemical: Effective for Class F fires.

*$CO_2$: Effective for Class B and Class C fires.

How to Use a Fire Extinguisher

1. Pull the pin.

2. Aim at the base of the fire.

3. Squeeze the lever.

4. Sweep side to side.

Standpipe Systems

• Internal piping network connected to fire-hose stations.
  

*Class I: For fire department use.

*Each main floor landing or intermediate landing of required stairs.

*On the roof if the stairwell does not have access to the roof.

*Each side of exist openings in horizontal exists.

*Exit passageways

*Class II: For trained personnel.

*Class III: Combination of Class I and Class II.

Types of Standpipe Systems by Water Supply

*Wet Standpipe Systems: Filled with water and pressurized.

*Dry Standpipe Systems: Not filled with water; connected to a water source during firefighting.

Combination Standpipe-Sprinkler Systems: Integrated with sprinkler systems to provide dual fire suppression capabilities.

Automatic Sprinkler Systems

• Network of pipes near the ceiling that automatically dispense water on a fire. Sprinkler systems are designed to activate quickly and suppress fires before they can spread, reducing property damage and protecting lives.

• Designed to extinguish or prevent the spread of fire.
  

*Sprinkler Installation Orientations:

*Pendent: Sprinkler heads are installed facing downward.

*Upright: Sprinkler heads are installed facing upward.

*Sidewall: Sprinkler heads are installed on the side of a wall.

*Concealed: Sprinkler heads are hidden behind a cover plate.

Sprinkler Head Coverage Area

Light Hazard: 130-200 sqft (12 -19sqm) per sprinkler head; 15-foot (4.5m) distance maximum between sprinkler heads

Ordinary Hazard : 130 sqft (12sqm) per sprinkler head; 15-foot (4.5m) distance maximum between sprinklers

Extra Hazard : Coverage area of 90-130 sqft (8 – 12 sqm) per sprinkler head, based on certain factors; 12-foot (3.6m) distance maximum between each sprinkler head

Alternate Fire Protection Systems

• Water Mist Automatic Sprinkler Systems: A fire suppression system that uses a fine mist of water to extinguish fires. Water mist systems are effective for a wide range of fire hazards and use less water than traditional sprinkler systems.

• Clean Agent Gas Fire Suppression Systems: A fire suppression system that uses a non-toxic gas to extinguish fires. Clean agent systems are often used in areas where water damage is a concern, such as data centers and museums.

• Carbon Dioxide ($CO<em>2$) Fire Suppression Systems: A fire suppression system that uses carbon dioxide gas to extinguish fires. $CO</em>2$ systems are effective for extinguishing fires involving flammable liquids and gases, but they can be dangerous to humans and should only be used in unoccupied areas.

Fire Detection and Alarm Systems

• Detect combustion products (smoke, heat, light) and provide early notification. Fire detection and alarm systems are essential for providing early warning of a fire, allowing building occupants to evacuate safely.

• Smoke Alarms: Detect smoke and give audible/visual warnings.
  

Smoke and Heat Detectors: Detect products of combustion or high temperatures.

Types of Fire Detectors

• Fixed-Temperature Heat Detectors: Activate when the temperature reaches a predetermined level.

• Rate-of-Rise Heat Detectors: Activate when the temperature rises rapidly.

• Flame Detectors: Detect the presence of flames.

• Manual Pull Stations: Allow building occupants to manually activate the fire alarm system.

Alarms

• Audible evacuation signals (bells, horns, etc.) and strobe lights. Alarms should be loud enough to be heard throughout the building and strobe lights should be visible to people with hearing impairments.

Conveying Systems

• Mechanical systems that move people and freight vertically and horizontally. Conveying systems are essential for providing access to different levels of a building and for transporting goods and materials.

Lifts (Elevators)

• Used to move people or freight vertically between floors.
  

*Down Collective Lift Control: As the car descends, landing calls are answered in floor sequence to optimize car movement.

*Full or Directional Lift Control: The lift responds to calls in floor order independent of call sequence, first in one direction and then the other.

Lift Machine Room

• Preferably located above the lift shaft. The machine room houses the machinery that operates the elevator, including the motor, gears, and control systems.

• Must be well-ventilated and machinery well secured.

Lift Safety Features

• Buffers: Located at the base of the shaft. Buffers are designed to cushion the elevator car in the event of a freefall.

• Overspeed Governor: Locks the governor when speeding. The overspeed governor detects when the elevator car is traveling too fast and activates the safety gear.

• Safety Gear: Hardened steel wedges slow down and stop the car. The safety gear is designed to stop the elevator car in the event of a cable failure or other emergency.

Classification of Elevators

• Passenger Elevators: Designed to carry passengers.

• Freight Elevators: Designed to carry goods and materials.

• Dumbwaiter: A small elevator used to transport food, dishes, or other small items.

• Manlifts: A type of elevator used to lift workers to different levels of a building or structure.

Types of Elevators

• Hydraulic Elevators: Use a fluid-driven hydraulic jack.
  

*Electric Lifts (Traction Elevators): Have a drive machine with an electric motor and pulley-like (grooved) drive sheave that holds cables that move the elevator car up and down.

Escalators

• Power-driven, continuously moving stairway system.
  

*Escalator Arrangements:

*Single bank

*Criss-cross

*Parallel

Travelators

• Also known as autowalks or moving pavements, provide horizontal conveyance. Travelators are often used in airports and other large facilities to help people move quickly and easily from one place to another.

Acoustical Control Systems

Acoustics

• Science of sound, including its generation, transmission, and effects.
  

Normal conversation 60dB

Whisper is about 30 dB

Noise above 70 dB over a prolonged period of time may start to damage your hearing

Sound Ratings

TRANSMISSION/ISOLATION RATINGS

• SOUND TRANSMISSION CLASS (STC)

• NOICE REDUCTION COEFFICIENT (NRC)

Sound Transmission Class (STC)

• Rates a material's ability to block sound transmission. STC ratings are used to evaluate the effectiveness of walls, floors, and ceilings in reducing noise transmission between spaces.

• A high STC value implies a high insulating property.

Noise Reduction Coefficient (NRC)

• Measures a material's ability to absorb sound. NRC ratings are used to evaluate the effectiveness of materials in reducing the amount of reverberation in a room.

• Ranges from 0.0 to 1.0; a higher value indicates better absorption.

Acoustical Design Considerations

• Surrounding Environment: The level of background noise in the surrounding environment can affect the design of acoustical control systems.

• Arrangement and Layout of Rooms: The arrangement and layout of rooms can affect the way that sound travels through a building.

• Shape of Rooms: The shape of rooms can affect the way that sound waves reflect and reverberate.

• Reflecting Surfaces: Hard, smooth surfaces reflect sound, while soft, porous surfaces absorb sound.

• Isolation of Vibration: Vibration from machinery and equipment can transmit noise through a building.

• Isolation of Impact: Impact noise, such as footsteps, can be disruptive and annoying.

• Isolation of Sound: Sound can travel through walls, floors, and ceilings.

• Background Noise: A certain level of background noise