Leswin D’cunha CH2M HILL Introduction to Wastewater Engineering Introduction to Engineering/Chabot...

Leswin D’cunha

CH2M HILL

Introduction to Wastewater Engineering

Introduction to Engineering/Chabot CollegeNovember 29, 2012

Copyright [insert date set by system] by [CH2M HILL entity] • Company Confidential

Education and Experience

Education 2004: Graduated high school, India 2008: Undergraduate degree in Biotechnology Engineering, India 2011: Graduate degree in Environmental Engineering, Illinois

Tech, Chicago

Career Experience 2010: Student intern at Oceanside WWTP, SFPUC 2011-present: Wastewater Process Engineer, CH2M HILL


What brought me here?

The Sanitation Crisis Only 31% use improved sanitation (2008) In rural India 21% use improved sanitation facilities

(2008) 638 million people defecate in the open; over 50%.

The Water Crisis 88% have access to drinking water from improved

sources (2008) Only 25% have drinking water on their premise Women, who have to collect the drinking water, are

vulnerable to a number of unsafe practices 67% of Indian households do not treat their drinking

water

INDIAPopulation: 1.2 billion

Source: UNICEF

Global environmental engineering firm• Planning• Design• Construction• Operation• Program Management

We help our clients build a better and more sustainable world in the areas of:

Energy

Environmental

Facilities

Resources

Transportation

Water


CH2M HILL Today

Headquartered in Englewood, Colorado More than 30,000 employees worldwide US$6.3 billion in revenue 100 percent owned by our employees Broadly diversified across multiple business sectors Performing work in more than 140 countries


The Top 20 Design Firms by Sector (ENR)

Wastewater Treatment 101


Typical Domestic Wastewater Characteristics

Pollutant Concentration (mg/L)

Total Solids (TS) 720

Total Dissolved Solids (TDS) 500

Total Suspended Solids (TSS) 210

Five-day Biochemical Oxygen Demand (BOD5) 190

Chemical Oxygen Demand (COD) 430

Total Nitrogen (TN) 40

Total Phosphorus (TP) 7

Fecal Coliform (#/100 ml) 10^4 – 10^6

Based on average flow of 120 gpd/cap Source: Metcalf and Eddy, 4th Ed.


Compliance Standards

Parameter 30-day average 7-day average

5-day biological oxygen demand (BOD5), mg/L

30 45

Total suspended solids (TSS), mg/L

30 45

Percent removal for both BOD5 and TSS

85

pH, s.u. Within the range of 6.0 to 9.0 at all times

Fecal Coliform Bacteria, MPN/100 ml

200 400

NPDES: National Pollutant Discharge Elimination System- Permit required to discharge treated wastewater to U.S. waters (Clean Water Act, 1972) Title 40 Code of Federal Regulations Part 133 (40 CFR 133)

- Secondary treatment regulation


Residential/Commercial

Industrial

Pump Station

Screening Grit Removal

Biosolids for Beneficial Reuses

Primary Clarification Bioreactor

Secondary Clarification

Filtration

Disinfection

Solids Thickening

Digestion

Solids Dewatering

Biogas

Landfill

Power and Heat Generation

Flare

Reclaimed Water

A Municipal Wastewater Treatment Plant

Discharge

Virtual Tour of a Municipal Wastewater Treatment Plant



Industrial

Pump Station





Filtration

Disinfection

Solids Thickening

Digestion

Solids Dewatering

Biogas

Landfill


Flare

Reclaimed Water

A Wastewater Treatment Plant

Discharge


Municipal Collection Systems

Sanitary sewer system: domestic wastewater only Combined sewer system: domestic and stormwater