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Water Conservation
Services
Facility Audits
A facility water audit is
a systematic review of a site that
identifies the quantities and
characteristics of all the water uses. A
water balance is completed to determine
locations and qualities of water used
throughout the facility. For example, in a
manufacturing environment there are many
important considerations the audit must
address. Some of these are necessary flow
rates, flow direction, water temperature,
and pertinent water quality parameters of
various water streams as they travel
throughout a plant. Water audits can range
from simple to very complex depending on the
type of facility being reviewed and the
amount of time the customer is willing to
invest in the review. The outline below
describes the basic information needed and
the process for completing a fairly complex
water audit.
To make the most of the
time spent on site, it is helpful to obtain
as much information about the physical
characteristics of the site beforehand. Some
of the tasks that should be completed in
advance so that the auditor is familiar with
what to expect during the site visit are
listed below:
- Gather, review, and
tabulate water/wastewater records, billings,
and costs. Review wastewater pretreatment
inspection reports if available.
- Identify contact
person(s) (plant engineer, maintenance
staff, plant manager).
- Send letter to
contact person confirming appointment and
outlining scope of site visit and
information needed.
- Review plant plans,
schematics of process flow, lot size,
irrigated area(s), building footprints, etc.
if they can be obtained in advance of visit.
- Gather and review
operating records from facility operator or
engineer. Examples of data to collect are:
- Cooling towers
treatment, sub-meter records.
- Boiler
maintenance data.
- Irrigation
systems: clock run times, number of runs
per week, area per zone or heads per
zone and head types, sub-meter data, if
any.
- Readings from all
meters that track water/wastewater use
in the plant.
- Pump run time
records.
- Energy use
records.
- Staffing numbers,
visitors, shifts, hours of operation for
various water using machinery and the
building in general, etc.
- Information on
other activities and processes that use
significant amounts of water.
- Reports from
prior water use or energy surveys
conducted for the site.
During the site visit,
gather as much additional data on how the
facility is operated and the process flows
as possible. Much of this information is
shared through meeting with those who
operate the facility, but a tour of the site
also provides important opportunities to
witness the actual operations and to ask
additional questions about procedures. At a
minimum, the site visit should include the
following:
- Meet with plant
personnel. Discuss water uses, water
conservation ideas, and any water
conservation measures that have been taken
in the past or are planned for the future.
Discuss and note proposed facility
expansions or equipment implementation plans
with plant personnel.
- Tour facility. If
allowed by customer, take photos of
important water usage operations for use in
the report and to maintain a visual memory
of the site.
- Identify water
sources, individual uses, volumes, disposal
methods, losses, treatment chemical uses and
costs, plant/site sub-meters. Make flow
measurements for major water use streams if
they are not sub-metered. Collect water
quality samples if reuse of some waste
streams is contemplated.
These steps may need to
be repeated over the course of a week or
two. Each site will be somewhat unique,
however, the following are key points or
typical water uses to investigate among the
commercial and government sector:
- Toilets and urinals
(estimated use per flush and number of
occupants and uses per day).
- Faucets (flow
measurement and number of occupants and uses
per day).
- Showers (flow
measurement and number of occupants and uses
per day).
- Dishwashers (Model
no., hours of operation, visual inspection,
water-saving features).
- Garbage Disposers
(Model no., hours of operation, visual
inspection).
- Plate cleaning
troughs (flow measurement, Model No., hours
of operation, visual inspection).
- Ice Making Machines
(Model no.; type (cube or flake); pounds of
ice produced; visual inspection; air-cooled
or water-cooled; flow measurement of
once-through cooling flow, where
applicable).
- Ice Cream/Frozen
Yogurt Machines (Model no.; visual
inspection; air-cooled or water-cooled; flow
measurement of once-through cooling flow,
where applicable).
- Water-cooled
Refrigeration Units (measure once-through
flow rate where possible, model no., and
capacity information).
- Miscellaneous Uses
(food thawing, cleaning, etc.).
- Leaks, drips.
- Cooling Towers
(Capacity, make-up water amounts, hours or
period of operation, cooling load, chemical
vendor, vendor reports, concentration
ratio).
- Single-Pass
(once-through) Cooling (identify uses such
as air compressors, vacuum pumps,
water-cooled condenser units, product
cooling, flow rate, hours of operation,
temperature).
- Evaporative Coolers
(capacity, check bleed-off water volume,
condition of equip., concentration ratio).
- Humidifiers
(capacity).
- Boilers/Steam
Generators (capacity, steam condensate
recovery, leaks, blowdown, "mixing valves").
- Water-cooled Heat
Pumps (measure flow rate if possible, model
no., and nameplate data for capacity,
contact equipment supplier for use data).
- X-ray/Film Processors
(hours of operation, flow rate, automatic
shut-off? Is it operational?).
- Rinse Baths (flow
rate, hours/duration of operation,
static/constant overflow/counter-current
type). Are there any automated controls to
manage water make-up, overflow rates, amount
of time parts are suspended above tanks for
drip back, etc.
- Type of washer (flow
rate, pounds of laundry washed per day,
number of loads washed per day).
- Water Reclamation
System in place?
- Steam Sterilizers
(flow rate, hours of operation, automatic
flow shutoff).
- Ethylene Oxide
Autoclaves (flow rates, hours of operation).
- Manual Washing
(method of cleaning, volume of water used).
- Vehicle Washing (flow
rates, condition of equip., hours of
operation, water recycle systems).
- Irrigation (area,
volume, period of operations, type and
condition of equipment, automatic controller
or manual).
- Landscaping (type of
landscaping, location of landscaping, site
conditions that would affect water use –
soil types, slopes, sun exposure,
visibility/use of area).
- Ponds and Fountains
(water recycle systems, automatic shut-off).
- Pools (fill
frequency, filter backwash frequency and
rate, cover present?).
- Ingredient (volume
and period of operation).
- Cleaning Operations
(rate and operation period).
- Conveyance (flow
rate, hours of operation, automatic
shut-off).
- Water/Wastewater
Treatment (reject volume, equipment
efficiency).
The interpretation of
data collected during the site visit and
initial data review steps is key to the
recommendations provided to the customer.
There may be instances where additional data
needs to be collected to confirm the
accuracy of flow estimates or assure the
feasibility of reusing a certain stream of
water for another purpose, for example. When
flow balances do not seem to match up to
actual billings, additional investigation
and measurements may be needed to confirm
that all water uses have been included and
estimates reflect actual site conditions.
The data evaluation steps for a typical site
efficiency assessment are:
Use the information
gathered and the measurements taken at the
site, estimate quantity and uses of water at
the site for various activities. Compare to
the annual water consumption records. A
water balance allocating at least 90 percent
of the water consumption for the site to the
water using activities at the site is a
reasonable result. If there is more than ten
percent difference between estimate and
actual total use, review site uses again to
ensure that all significant water uses have
been considered in the balance. If balance
was complete and error free and actual is
less than balance, meter may be registering
low. Have mainline meter checked for
accuracy. If balance is lower than actual
use, a leak may exist.
Identify potential
conservation actions,
savings, and costs
Based on the amount of
water used for various operations on site as
compared to other more water efficient
methods for achieving the same end result,
identify potential water conservation and
estimate the water savings and
implementation costs for the conservation
actions considering water, wastewater,
energy, and other associated (chemical,
labor, transportation, reduced/increased
production time, etc.) costs or cost
savings, where applicable.
Cost-effective
conservation actions for the commercial and
government sector are opportunities that pay
for the implementation costs with water,
wastewater, and energy savings within 3-5
years. What a particular business considers
a reasonable payback period typically
depends on the type of facility. Some
private industries that see rapid changes in
plant infrastructure as a result of product
advancements, like the computer industry,
may view 6 months as a maximum payback
period, while public sector facilities that
may use the same facility without much
change for 50 years may be comfortable with
longer payback periods approaching 5 years
or more. The reports developed for customers
will include measures that are within the
payback identified by that particular
customer as an appropriate length to
consider. In general projects with paybacks
of 5 years or less are thought to be worth
including in a list of feasible measures.
Summarize the findings
and recommendations from the water audit
process in a short, succinct report that the
customer can use to obtain support for
implementing projects and for budgeting for
them in the next several years. This report
should briefly describe the activities on
site and the factors that influence water
use, provide a consumption history for the
site, summarize the results of the water
balance, summarize feasible conservation
opportunities, including costs, savings
(labor, water, sewer, energy, chemicals,
etc.), and paybacks and/or return on
investment for conservation measures with
paybacks of 5 years or less, and a
prioritized schedule for completing projects
considering other upcoming work at the site
into which conservation projects might be
incorporated.
Provide the customer with
a copy of the report and discuss the options
and alternatives presented in report. If the
customer contact person agrees, include
management in these discussions. Aquavative
staff members will maintain contact with the
customer’s representative for two or three
years as projects are implemented. They will
answer questions, provide consumption data,
obtain project cost figures, determine
before and after water use, and discuss
performance and affects (positive and
negative) the project has had on plant
operations.
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DROUGHT MONITOR