DWT
What is the difference between DWT and WWT
Drinking water treatment focuses on treating source water, often much cleaner, while WWT focuses on industrial waste and sewage.
______ is a graphical representation of rainfall intensity versus time, most commonly displayed as a bar graph
Hyetograph
What is the difference between a storm sewer and a sanitary sewer
A storm sewer carries stormwater, a sanitary sewer carries only sewage
What is a PS pollutant?
Point source pollution is any single, identifiable, and localized source from which pollutants are discharged into the environment, such as a pipe, ditch, ship, factory smokestack, or tunnel
What does O&M refer to?
Operations and Management, day to day costs associated with plant service
What are the most common components of a drinking water treatment train?
_____is a graph that shows how a river, stream, or drainage system's water flow or water level changes over time at a specific point.
Hydrograph
Before modern sewer systems, most communities used "_____ ___" systems, such as the cloaca maxima to drain sewage away from cities. This inspired modern sanitary sewer design. To improve this design, sometimes the sewage needed to be "pumped" up to maintain flow.
Gravity fed, pumped
What is a NPS pollutant?
Nonpoint source (NPS) pollution is contamination that does not come from a single, distinct, and identifiable location (such as a factory discharge pipe or a wastewater treatment plant). Instead, it results from multiple, diffuse sources spread across a broad area
What is CAPEX?
Capital Expenditures
What does CT tell us for DWT?
Contact Time, expressed in minutes, for disinfection in a DWTP
A mathematical model of a watershed is a set of equations and computer algorithms that simulate how water, sediment, and nutrients move across a land area (a drainage basin). Give two examples of math models used in hydrology
Runoff estimation model, rainfall intensity model, CN Method, Green Ampt Model, Exeedence Probability Model, IDF curve, the rational method.
Wastewater, also called "____" enters the "_____ _____" where it is then pre-treated by coarse bar screens, fine screens, and grit removal. This helps remove any debris within the "_____" before it gets to the WWTP's pipes
Influent, collection system
What does the Streeter-Phelps equation describe?
The Streeter–Phelps equation describes how dissolved oxygen (DO) levels change downstream in a river or stream after organic waste (measured as biochemical oxygen demand, or BOD) is introduced
Give an example of CAPEX
Construction of treatment tanks, buildings, and collection systems.
Pumps, blowers, clarifiers, filters, and disinfection equipment.
Sewer extensions and replacement of aging infrastructure.
Land acquisition, engineering, permitting, and construction management.
Upgrades needed to meet more stringent discharge requirements.
What are the similaries between a DWTP and a WWTP?
Both facilities utilize sequential physical, chemical, and biological processes—including sedimentation, filtration, and disinfection—to remove contaminants and protect public health and the environment.
What does the rising limb on a hydrograph describe?
the upward-sloping portion where streamflow or river discharge increases from the start of a precipitation event up to the point of peak discharg
What is the purpose of primary treatment
The primary clarifier reduces the amount of suspended solids and organic material entering the biological process.
How does BOD affect fisheries in Massachusetts?
BOD lowers DO, which in turn affects species very sensitive to oxygen.
Give an example of O&M
Electricity and fuel.
Chemicals and laboratory supplies.
Employee salaries and benefits.
Mechanical repairs and equipment replacement.
Sludge processing, transportation, and disposal.
Regulatory monitoring, reporting, and compliance.
How do we assess source water quality?
Turbidity, suspended solids, color, temperature
pH, alkalinity, hardness, metals, nutrients, organic matter
Bacteria, viruses, protozoa, algae
PFAS, pharmaceuticals, microplastics, other contaminants of concern
Seasonal changes, storms, drought, temperature changes, changing contaminant concentrations
the portion of a stream or river's flow that comes from delayed subsurface pathways rather than direct rainfall runoff
Baseflow
What is the purpose of secondary treatment? Is the water safe after and why or why not?
The purpose of secondary treatment is to reduce the amount of remaining biodegradable organic matter through biological processes. It is not safe and must be disinfected after.
How are temperature and DO related?
Temperature and dissolved oxygen (DO) have an inverse relationship: as water temperature increases, the amount of dissolved oxygen in the water decreases
Compare WWTP and DWTP operations. How much more expensive is WWTP operations and why?
WWTP is 2-3x higher because water is much much dirtier and difficult to treat. Includes industrial wastes