Lecture 12 Waste Collection System Design

Front

What is the formula for calculating the number of services per vehicle load (N)?

Back

N = (C x D)/W, where C = Vehicle capacity (m3), D = Waste density (kg/m3), W = Waste generation/residence (kg/service)

Front

How is the time required to collect one load (E) calculated?

Back

E = N x L, where L = Loading time/residence, including on-route travel.

Front

What factors are considered in estimating the number of loads (n) a crew can collect in a day?

Back

Workday length (t), administrative and break time (t1), hauling and travel time (t2), and collection route time (t3).

Front

What is the formula for administrative and break time (t1)?

Back

t1 = A + B, where A = Administrative time and B = Time for breaks and lunch.

Front

What does the formula for hauling and other travel time (t2) include?

Back

t2 = (n x H) - f + G + J, where H = Time to travel to disposal site, f = Time to return from site to route, G = Time to travel from staging garage to route, J = Time to return from disposal site to garage.

Front

How is the time spent on the collection route (t3) calculated?

Back

t3 = n x E.

Front

What is the formula for calculating the length of the workday (t)?

Back

t = t1 + t2 + t3.

Front

What is the formula for calculating the number of vehicles and crews (K)?

Back

K = (S x F)/(N x n x M), where S = Total number of services, F = Frequency of collection, M = Number of workdays/week.

Front

What are the components of annual vehicle and labor costs?

Back

Vehicle costs = Depreciation + Maintenance + Consumables + Overhead + License + Fees + Insurance; Labor costs = Drivers salary + Crew salaries + Fringe benefits + Indirect labor + Supplies + Overhead.

Front

What long-term trends are important for planning in waste collection systems?

Back

Solid waste generation rates and composition.