Activity 5 - Water conservation

GEOG 200 Fall 2023 - Activity 5 - Water conservation begins at home Please complete by 11:59pm PST Saturday November 4, 2023 Upload a Word Doc version of this Google Doc to Canvas with your answers in the tables ( see Tasks A-E ). A satisfactory assessment will be given for successful completion of Tasks A-E. Billions of gallons of treated drinking water (since all of the water we use in our homes is treated to the highest standard no matter what we use it for - bathing, toilet flushing, watering the garden, washing the car, etc.) are unnecessarily wasted due to leaks and inefficiencies. Water has historically been very cheap because of subsidies and the invisible backpack of costs passed on to others. So we haven’t cared about it or conserved it. In many places, it was provided as an unmetered service (flat monthly fee) and not with a commodity tariff (service fee plus metered volumetric use per month). Nowadays, most utilities have billing systems that meter water use to residential homes (but unlike with electricity, not to individual apartments) and so households pay more or less for their water depending on how much they use. Where I live, in Oakland which is serviced by EBMUD (who I used to work for from 1990-92 as a water conservation specialist), this is the current residential tariff system and this is approximately how a bill is calculated (rounded to the nearest ccf). Water Bill 0-14 ccf per 60 days = $4.99/ccf >14- 32 ccf per 60 days = $6.86/ccf over 14 ccf >32 ccf per 60 days = $9.06 over 32 ccf So, let’s assume a household of 4 uses the following average amounts of water - 50 gpd per person, 100 gpd per person, 200 gpd per person, 300 gpd per person - what will be the bill for the two months? The red is what you measure/estimate. gal/day per person * no persons = gal/day gal/day * days per bill = gal per bill gal per bill / gal/ccf = ccf per bill 0-14 ccf * $4.99/ccf = tier 1 portion of bill (>14-32 ccf) - 14 * $6.86/ccf = tier 2 portion of bill 6(>32 ccf - 32) * $9.06/ccf = tier 3 portion of bill tier 1 + tier 2 + tier 3 + service charge = $/bill

gal/day per person no persons gal/day days per bill gal per bill gal/ccf ccf per bill ccf @ $4.99/ccf (0-14) ccf @ $6.86/ccf (>14-32) ccf @ $9.06/ccf (>32) Service charge $/bill 50 4 200 60 12000 748 16 14 2 0 $65.40 $148.98 100 4 400 60 24000 748 32 14 18 0 $65.40 $258.74 200 4 800 60 48000 748 64 14 18 32 $65.40 $548.66 300 4 1200 60 72000 748 96 14 18 64 $65.40 $838.58 60 5 300 60 18000 748 24 14 10 0 $65.40 $203.86 Task A - Fill out the blank bottom row using the correct math - You can put your estimated gallons per person per day along with the number of people in your household and work out what your bill would be if you lived in Oakland - or you could do the math for your own water utility if you know it and can find the rates. OK, having gone through that explanation, now you can do some conservation math! These following calculations can be applied to any facility, big or small. It’s simple algebra = X * Y * A/B = M but applied to real-life issues that have $ implications. Dripping Taps Many of us have dripping taps - in the bathroom, or out in the garden. We think a little drip won’t make a difference - but it can. If we put a measuring beaker underneath, leave it for a given number of minutes, and record the volume in milliliters, we can calculate how many gallons that is over a year and how much that water costs. The red is what you measure (in ml and min). ml ÷ min * 60 min/hr * 24 hours/day * 365 days/yr = volume wasted ml/yr ml/yr ÷ 1,000 ml/l ÷ 3.785 l/gal = volume wasted gal/yr gal/yr ÷ 7.48 gal/ft 2 ÷ 100 ft 2 /ccf = ccf billing units wasted/yr ccf billing units wasted per yr * $/ccf = $/yr wasted, i.e. savings per year from fixing washer ml vol min min/ hr hr/day day/yr ml/yr ml/l l/gal gal/yr gal/ft 2 ft 2 /ccf ccf/yr $/ccf $/yr e.g. 750 e.g. 45 60 24 365 8760000 1000 3.785 2314 7.48 100 3.09 $6.86 $21.20 600 40 60 24 365 7884000 1000 3.785 2083 7.48 100 2.78 $6.86 $19.07 Task B - Fill out the blank bottom row for a dripping tap in your home using the correct math - if there isn’t a dripping tap now, leave one slightly turned on so it drips as a simulation - please don’t waste the water after! - Drink it or use it on plants, etc. Retrofitting Shower Heads

the water to the tank, flush the toilet with a full flush, and then manually fill it up to the normal fill level with a measuring container to determine the volume (if you use quarts or pints, there are 4 quarts and 8 pints to a gallon). The red is what you measure/find out. gpf * no people * flushes per person per day = gal/day gal/day * 365 day/yr = gal/yr gal/yr ÷ 7.48 gal/ft 2 ÷ 100 ft 2 /ccf = ccf billing units/yr ccf billing units per yr * $/ccf = $/yr $/yr old toilet (e.g. 3.5 gpf) - $/yr 1.28 gpf toilet = $/yr savings from replacement Here’s a table for the calculation - there’s no example - it should be easy for you to do it yourself by now. gpf people flush per person/day day/yr gal/yr gal/ft 2 ft 2 /ccf ccf/yr $/ccf $/yr 1.6 5 4 365 11680 7.48 100 15.6 $6.86 $107.02 1.28 5 3 365 7008 7.48 100 9.4 $6.86 $64.48 0.32 0 1 0 4672 0 0 6.2 Savings $42.54 Task D - Fill out the two blank rows (one for your current toilet, the other for a 1.28 gal/min ultra low flow) using the correct math then fill out the savings. Turning the Tap Off While Brushing Teeth You hopefully don’t do this, but many people do….and it’s amazing how much water this can waste. To brush one’s teeth, all that is really needed is a short 1-2 second burst to wet the brush head and paste, a 3-4 second burst to clean the brush head, and a 2-3 second burst to take a sip of water to rinse and spit. So, let’s say 10 seconds to be conservative. And let’s assume that a person brushes their teeth twice a day for 60 seconds with an additional 10 seconds for the brush and rinse management. If we know the gallons per minute flow rate of the faucet when turned on, we can calculate the water wasted. The red is what you measure. gal/min ÷ 60 sec/min = gal/sec gal/sec * 70 sec/brushing = gal/brushing

gal/brushing * 2 brushing/day * 365 day/yr * persons = gal/yr gal/yr ÷ 7.48 gal/ft 2 ÷ 100 ft 2 /ccf = ccf billing units/yr ccf billing units per yr * $/ccf = $/yr with tap running Repeat using 10 sec/brushing for $/yr without tap running and subtract from $/yr with tap running for $/yr savings (or you could multiply $/yr with tap running by 60/70). gal/ min sec/ min gal/ sec sec/ brushing gal/ brushing brushing/ day day/yr people gal/yr gal/ft 2 ft 2 /ccf ccf/yr $/ccf $/yr 4 60 0.07 70 4.9 2 365 5 17885 7.48 100 23.9 $6.86 $163.96 2 60 0.03 10 0.3 2 365 5 1095 7.48 100 1.5 $6.86 $10.29 2 0 0.04 60 4.6 0 0 0 16790 0 0 22.4 Savings $153.67 Task E - Fill out the two blank rows (the assumed 70 sec and 10 sec tap uses in your household) using the correct math then fill out the savings. Hopefully this will have been an eye-opening assignment to the opportunities for water waste, water conservation, and financial savings. Download your version of this Google doc as a Word Doc and then upload it to the Canvas assignment nown you have filled it out. Thanks - that’s a wrap!