Wastewater Grade 1
Density of water
1 at 4 degree Celsius
What is F.O.G?
Fats Oil and Grease
Aerobic digestion
The breakdown of waste by microorganisms in the presence of dissolved oxygen
National Pollutant Discharge Elimination System (NPDES)
•1972 clean water act •Major goal-reduce or eliminate pollutants
Disadvantages to ponds
•May produce odors •requires a large area of land •treatment is inconsistent depending on weather •may contaminate ground water •can leave high levels of suspended solids
Fusible plug
•Melts at a specific temperature to prevent explosion. •Can be found on chlorine cylinders
Ponds in parallel
•More even distribution of flow. •Provides redundancy
Aerobic Lagoons
•Oxygen supplied by natural surface aeration or mechanical aeration and photosynthesis. •when waste introduced, usually takes 7-12 days for algae growth.
80-90% rule
•Prior to exceeding 80% of hydraulic flow: Engineering evaluation, plans and specs, eliminate extraneous flows, funding sources. •Prior to 90% of permitted hydraulic flow: Obtain permits, if construction is necessary. Final plans and specs and construction schedules.
Operators license may be suspended or revoked for?
1. Fraud or deception 2. Incompetence or inability to perform job duties 3. Not using reasonable care or judgement
With a vacancy in the ORC, how long does a system owner have to designate a new or back up ORC?
120 days
How long does an ORC it back up ORC have to notify the commission and the regional office (DWR) upon vacation a position?
14 days
Application for NPDES permit renewals are required how many days before the permit expires?
180 days
How long do you have to report a bypass to DWR?
24 hrs
How long do facility owners need to keep copies of all DMR's?
3 years
DMR's must be submitted within how many days following the end of the calendar month?
30 days
How long does an operator have to notify the commission of change of address?
30 days
What regulation sets standards for the safe handling and use of sewage sludge?
40 CFR 503
Square feet in an acre
43,560 square feet
Sand filter
A gravity filter for cleansing water or purifying effluent, consisting of layers of coarse stone, coarse gravel and sand becoming finer toward the top.
Eutrophication
A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria. Eventually leads to "death" of a body of water.
Bar screens/racks
Bar racks •usually manual •3-4" spacing Bar screens •usually mechanical 3/8-2" spacing •if failure, bypass to rack
BOD
Biological Oxygen Demand, amount of dissolved oxygen needed by aerobic microorganisms to break down organic material.
What is a combined sewer system?
Both sanitary waste and storm water.
What is a sanitary collection system?
Carries waste from households and commercial establishments in the city or district and possibly some industrial waste.
Floc
Clumps of bacteria and particles or coagulants and impurities that have come together and formed a cluster.
What is Storm Sewer collection system?
Collects storm runoff from streets, land and roofs
dosing tank
Deliver wastewater from the septic tank to the next stage of treatment usually to a sand filter or leach field in a control manner
Household wastewater
Domestic or sanitary wastewater from toilets, sinks, showers etc...
Seasonal flow
Due to increased rainfall, hurricanes, drought etc...
Daily flow
Due to morning and evening increases in flow caused by showering, cooking, dishes etc...
Hydrologic cycle
Explains how water moves through the earth and illustrates the importance of maintaining clean water. Treatment of wastewater discharges are needed to protect human health and environment
Types of wetland vegetation
Floating, Submerged, Emergent (Reeds, cattails and bulrushes)
Stale wastewater characteristics
Foul odor, septic or sulfur smell. Dark grey or black in color, little to no oxygen, long time in collection system. Corrosive difficult to treat.
Infiltration
Ground water or storm water that invades the sanitary sewer through brakes, open joints, or corrosion.
Tertiary treatment
Highest form of wastewater treatment that includes removal of nutrients, organic and solid material, along with biological & chemical polishing. Ex: membranes, filtration, absorption, electrodialysis, coagulation-sedimentation, reverse osmosis, chemical oxidation and polymers.
Splash pads
Keeps the incoming wastewater from eroding the side or bottom of pond
Fresh wastewater characteristics
Low odor, sometimes musty/earthy. Light grey in color, more oxygen less, time spent in collection system.
Dissolved oxygen
Measure of water quality indicating free oxygen dissolved in water. Must be analyzed within 15 mins of collection. However, on site or immediate analysis is recommended due to the unstable nature of dissolved oxygen in samples
Biological treatment
Microorganisms stabilize the organic matter by converting it to a form that is easier to refine from the wastewater
When does the application for exam need to be sent to state?
Must be postmarked 30 days prior to date of exam.
What is the pH limit for NPDES permits in the state of NC?
No lower than 6, no greater than 9
How long can a back up ORC fill in for a missing ORC?
Not to exceed 40% of visitations required in a calendar year OR not to exceed 120 consecutive days.
What is pond turnover?
Occurs during temperature change, in spring or fall. Causes solids at bottom of the pond to rise to surface.
Federal Water Pollution Control Act of 1972
PL 92-500 grants EPA authority to: •Regulate discharges •Define my control technologies •Establishes effluent limitations •Obtain info-reporting & inspections •Take enforcement actions
WPCSOCC
Pollution Control Systems Operator Certification Common
Photosynthesis
Process that organisms, with the aid of chlorophyll, use to convert carbon dioxide into oxygen. Using sunlight as energy source.
When do you report spills?
Sanitary sewer - greater than 1000gal to the ground or any amount that reached surface waters.
Types of collection systems
Sanitary, storm, combined
Stabilization pond
Take raw wastewater and treat it before discharge to another pond or process.
Who is responsible for understanding and meeting all permit requirements?
The permittee.
What is shredding?
The purpose is to shred solids and leave them in the wastewater.
Single pass sand filter
Treated water only passes through once
Secondary treatment
Treating wastewater biologically, by using microorganisms to decompose the suspended organic material; occurs after primary treatment
Describe a UV system
Ultraviolet radiation •disinfects by damaging the genetic material of the cells so that they can no longer grow or reproduce •250-270 effective range
Disinfection
Used to ensure all pathogenic organisms are destroyed at effluent. Methods: chlorine, UV, ozone
Temperature
Warmer temps create more biological activity Large fluctuations in temp and ph can be toxic to microorganisms
Influent
Wastewater entering a treatment process or system
Effluent
Wastewater leaving a treatment process or system
Inflow
Water discharged into a sewer system and service connections from sources other than regular connections ie: flow from yards drains, foundations, ground access and manhole covers. Direct discharge into the sewer rather than a leak.
Recirculating sand filter
Water is treated and pumped back through the sand filter and retreated. This increases treatment efficiency and quality of the effluent
Owner of a plant must designate an ORC and back up ORC within?
•60 days prior to wastewater being introduced into new system. •120 days of change of classification •Upon vacancy of ORC or back up ORC position
Grit channels
•Allow the wastewater velocity to be reduced. (Range: 0.7 - 1.4, Ideal: 1ft/sec). •Objective is to keep the lighter organic material in suspension and flowing to the next treatment unit while allowing the grit to settle.
Submerged inlet
•Allows wastewater to be more evenly distributed into the pond, preventing disturbance by the flow. •Submerged outlet keeps scum from escaping pond at effluent.
Clean Water Act (1972)
•Authorizes inspections and monitoring to determine compliance •Types of monitoring: -self monitoring -compliance monitoring
Ponds in Series
•Can give better treatment but the first ponds can become over loaded. •No redundancies available.
A telephone report shall be made asap but no later than 24 hrs after the occurrence of...
•Failure of a collection system, pumping station or treatment facility. •Discharge of significant amount of waste which are abnormal in quantity or characteristic. •Process unit failure.
What is a dry well?
•Have pumps outside of the water •usually 2 pumps alternating •pumps are easier to work on but still in a confined space •usually seen in large pump stations
Illegal connections
•Hydraulic loading can cause washout of the grease and insufficient capture •Build up of solids (sludge) can cause hydraulic loading •regular pumping/clean out is needed to maintain the grease trap or interceptor
Grit removal
•In this step, heavy but fine material such as sand and gravel is removed from the wastewater. This material is also disposed of in a landfill. •grit is heavier particulate that doesn't break down •causes excessive wear in pumps and take up space in digesters and can clog pipes
Anaerobic lagoon
•Little to no oxygen throughout. •treatment depends of fermentation of the sludge at the bottom
Microorganisms
•Living creatures that are too small to see with the naked eye. •Some microorganisms use the waste in wastewater for food and thus remove or alter much of the undesirable matter.
Polishing pond
•Located at end of process and receives water from another pond or trickling filter. •Use as tertiary treatment before discharge to water body.
ORC responsibilities include...
•Properly manage, operate and maintain plant. •Document daily operations •Certify by signature all monitoring and reporting information •Notify owner within 24 hrs of overflows, spills, bypasses and violations. •Notify owner in writing of needed repairs. •Be available
How is a spill reported?
•Report by telephone to a person (not voicemail) within 24hrs •Written report within 5 days
What are the consequences of intentionally falsifying records by an operator?
•Revocation of certification •A fine •Imprisonment
Septic tank baffles
•Slow disturbance of influent water. •prevent settleable and floatable solids from exiting septic tanks.
Grade 1 required analysis
•Temp •Dissolved Oxygen (DO) meter •Chlorine Residual •Settleable solids •Biochemical Oxygen Demand (BOD) •pH
What is the result when violations exceed the 20% limit?
•Up to $25k fine per day of violation. •Enforcement may be taken by the NC DMR.
Facultative Lagoons
•Upper portion is aerobic •lower is anaerobic
40 CFR Part 136
•code of regulations for labs •preservation, containers and holding times
What are wet wells?
•have submersible pumps •a float system controls when Pomona come on and off •usually 2 pumps alternate to save wear and tear
