PROGRAMS AND PLANS: Implementation of the Protocol for Collecting and Processing Surface-Water Samples for Low-Level Inorganic Analyses
In Reply Refer To: July 15, 1993
Mail Stop 412
OFFICE OF WATER QUALITY TECHNICAL MEMORANDUM NO. 93.11
Subject: PROGRAMS AND PLANS: Implementation of the Protocol
for Collecting and Processing Surface-Water Samples
for Low-Level Inorganic Analyses
PURPOSE OF THIS MEMORANDUM
For 2 years, the Office of Water Quality (OWQ) has been developing
a new field protocol for the collection and processing of samples
for low-level inorganic analyses. The purpose of this memorandum
is to announce the implementation date for the protocol and to
address issues of concern to Water Resources Division (WRD)
personnel. Several issues are covered: (1) reasons for the
protocol; (2) date of implementation; (3) what is meant by
"implementation"; (4) programs and projects affected, including
logistical considerations and equipment needs; (5) training needs;
and (6) answers to some specific questions that frequently have
been asked.
REASONS FOR THE PROTOCOL
The protocol was developed and is being implemented to improve and
assure the quality of data produced by WRD in the operational
program. It addresses a recognized need for improvement in
methods to enable WRD to meet its mission of describing the
quantity and quality of water resources. Through employment of
the protocol, WRD will produce more accurate, quality-assured,
inorganic data.
More specifically, the necessity for the protocol is detailed in
a series of OWQ Technical Memorandums, beginning with 91.10,
describing problems with the quality of existing trace-element
data for filtered samples. In that memorandum, two key points
were made. First, research projects in several geographic areas
demonstrated that filtered trace-element concentrations for many
elements are well below 1 microgram per liter (ug/L) (down to
a few nanograms per liter for certain elements). Comparing some
of the research data to National Stream-Quality Accounting Network
(NASQAN) results implied probable contamination in the U.S.
Geological Survey data. Second, studies on equipment blanks and
actual field samples demonstrated an unacceptable level of
contamination from random and systematic sources--mostly from
sample collection and field processing--for at least eight trace
elements. Based on these findings, the OWQ determined that (1)
changes were needed in field methods, field equipment, field
supplies, and associated quality assurance practices; (2) field
quality-control (QC) sampling needed to be instituted; and (3)
increased QC was needed on blank water and other supplies. The
resultant protocol is the summation of all of the needed changes
and refinements.
IMPLEMENTATION DATE
October 1, 1993, is the date the WRD will implement the new
protocol. By that time, the OWQ will have (1) developed and
tested the protocol, (2) identified appropriate equipment and
supplies needed to implement the protocol, and (3) established a
new laboratory method to analyze large numbers of filtered samples
for low levels of trace elements (using a new method for
inductively coupled plasma/mass spectrometry (ICP/MS) together
with existing methods). Protocol documents currently in
circulation are Drafts. The OWQ will issue a Technical Memorandum
to formally present the protocol as Division policy on October 1,
1993.
IMPLEMENTATION DEFINED
Implementation means that from October 1, 1993, onward, WRD will
use the protocol for all programs and most projects.
For new programs and projects developed after this date, the
protocol will be the standard operating procedure (SOP) for the
production of inorganic data. The protocol will be the SOP for
collecting and processing samples for major ions and nutrients, as
well as trace elements. Thus, for new projects, the protocol
should be used whenever inorganic samples are collected, even if
trace-element samples are not collected (see "Commonly Asked
Questions" for a more detailed discussion). A few projects where
only major ions are collected or where work is being done in a
highly contaminated environment may not require use of the
protocol. These projects must generate suitable and adequate QC
data to ensure that the environmental data being produced are not
contaminated.
For existing programs and projects, the protocol should be applied
as the SOP as soon as possible. This implementation may take
up to a year to implement in all WRD programs and projects.
NAWQA will begin using the protocol--as modified for ground
water--in a pilot manner this summer. NASQAN and Benchmark will
begin using the protocol as SOP at the beginning of fiscal year
(FY) 1995 (October 1, 1994). This timing will coincide with
implementation of a redesigned NASQAN program. However, Districts
that wish to do so are encouraged to begin using the protocol for
NASQAN and Benchmark stations as soon as possible. The OWQ will
work with such Districts to help implement the protocol, but
cannot pay for new sampling equipment and additional supplies.
PROGRAMS AFFECTED
All WRD operational programs and projects are affected by
implementation of the protocol. As described above, after
October 1, 1993, all new projects should use the protocol as
the standard SOP. For existing programs or projects, full
implementation will depend on several logistical considerations.
Most aspects of the protocol (such as the equipment cleaning)
are relatively easy and inexpensive to implement. Those portions
should be initiated as soon as possible. In addition, generation
of QC field blanks is both necessary and comparatively simple to
implement. The field QC data will verify if contamination
problems exist that need to be addressed.
The protocol lists sampling equipment and supplies that OWQ has
tested and established as capable of meeting protocol requirements
(see attachment 1). Appropriate samplers are available now from
the Waterways Experiment Station and supplies will be available
from the Ocala Quality Water Service Unit by October 1, 1993.
Because the equipment tested to date does not cover all sampling
environments, full implementation of the protocol is impossible
under all conditions (for example, under ice sampling). However,
to improve data quality, OWQ suggests implementation of
as much of the protocol as practical as quickly as possible.
TRAINING
As part of the protocol testing, one District per Region has
received training and has agreed to provide future training to
other personnel in use of the protocol. Other Districts should
arrange training through the Regional Water-Quality Specialist.
Field training has shown that the protocol (1) is easy to
follow, (2) adds little time at a site when two-person sampling
crews are used and equipment cleaning is done in the office, and
(3) can be effectively implemented with about 2 days of training
followed by some practice. The basis for success is development
of an awareness of the potential for contamination and the desire
to carefully employ the procedures. Field personnel who are
implementing the protocol are doing so enthusiastically because of
measurable improvement in the quality of data.
COMMONLY ASKED QUESTIONS
Question 1: This protocol is for surface-water sampling--
shouldn't it include ground-water sampling?
Answer: Ground-water sampling is being addressed through several
efforts concurrent to development of this surface-water
protocol. A draft document titled "Protocols and procedures
for collection of ground-water-quality data" by Wilde, Lapham,
and Koterba contains information parallel to that found in the
surface-water protocol. In addition, the OWQ is developing a
National Field Methods Manual that will contain succinct
protocols for surface-water and ground-water sampling. Thus,
expanding this protocol to include ground-water sampling would
be duplicative.
Question 2: Trace elements are reported at ug/L levels, but
nutrients and major ions are reported at milligram per liter
(mg/L) levels. Why does this protocol include nutrients and
major ions?
Answer: There are two reasons why nutrients and major ions were
included in the OWQ testing and subsequently in the protocol.
First, several nutrient schedules have 0.01 or 0.001 mg/L
reporting limits. These are actually ug/L reporting levels,
and many ambient conditions include nutrient concentrations
in this range. The cleaning, QC, and other items included
in the protocol are necessary to produce good-quality nutrient
data at these levels.
Second, given that the protocol is necessary to ensure good-
quality data for nutrients and especially for trace elements,
it would be counterproductive for most programs and projects
to use a separate protocol--based on different equipment and
supplies--for collecting samples just for major ion analyses.
Question 3: Many samples are collected for unfiltered analyses;
the protocol is for filtered samples. How does the protocol
apply to unfiltered samples?
Answer: The focus for protocol development was on filtered
samples because these have the more rigorous requirements
to reduce contamination levels. However, experiments clearly
show that the sample collection step is a major source of
contamination for a number of trace elements (see OWQ
Technical Memorandum 92.05). Therefore, on samples having
low to moderate concentrations of suspended sediment, use of
the protocol on unfiltered samples will be necessary to avoid
the production of contaminated trace-element data. For
samples having high concentrations of suspended sediment, the
concentration of trace elements extracted from the sediment
will swamp contamination added in the sample collection step.
Unfortunately, the actual level of suspended sediment at which
contamination is overwhelmed by extracted concentrations of
trace elements will vary by element, sampling site, time of
year, and other factors. Because the actual level will never
be known at the time of sampling, commencing October 1, 1993,
the protocol will be the Division SOP for all unfiltered as
well as filtered samples collected for inorganic analyses.
In a related matter, in 1992, the National Water Quality
Laboratory (NWQL) instituted an in-bottle digestion method
for unfiltered samples that has greatly reduced the potential
for contamination while increasing the precision of results.
Question 4: Are two-person sampling crews always necessary?
Answer: Two people are needed to do the "clean hands/dirty
hands" technique. Districts that use two-person crews have
found that they (1) produce better quality data, (2) save
time, and (3) are worth the cost. Aside from improperly
cleaned equipment, use of one person will probably be the
greatest potential source of contamination in sample
collection and processing. Based on field experience of WRD,
university, and other agency scientists, single-person
sampling from bridges, cableways, and metal boats will produce
contaminated samples.
In addition to the contamination issue, two-person crews
promote safety.
Question 5: Do I have to spend $2,000 on a D-77?
Answer: For some sampling circumstances, there are other, less
expensive alternatives to D-77 samplers. For wading
situations, a DH-81 with a plastic bottle is acceptable and
inexpensive. The metal rod can be covered with an inexpensive
piece of electrical-type shrink tubing. For low-velocity
situations (< 1.5 ft/s), a weighted-bottle sampler can be
used. HIF has a prototype for a noncontaminating weighted-
bottle sampler. For sampling from a bridge or a boat, a
frame-type, bag sampler can be fabricated for about $150. The
OWQ will obtain drawings for the frame samplers and provide
them to all Districts prior to October 1, 1993.
Use of other sampler types is not certified by the OWQ because
(1) the designs allow potential contact of water with metal
surfaces, and (2) tests conducted and reported by OWQ show
consistent contamination at unacceptable levels. OWQ testing
has shown the samplers included in the protocol to be
acceptable for low-level inorganic sampling. If you want to
use other samplers, you are responsible for generating
adequate tests and QC data to substantiate that your
objectives can be met with each other sampler.
Question 6: Dedicating a vehicle specifically for water quality
may be financially infeasible under all conditions in every
District. Is this necessary? Are there alternatives?
Answer: A dedicated, specifically cleaned space is necessary for
sample processing. A dedicated vehicle is preferable.
However, a specifically dedicated space within a vehicle might
suffice. Such dedicated space should be separated from the
remaining space in the vehicle. Also, use of a multi-purpose
vehicle will require a higher frequency of QC data to ensure
lack of contamination in processed samples. Perhaps a small
camper trailer would be an acceptable alternative to either a
dedicated vehicle or dedicated space within a vehicle. Ideas
for other alternatives should be communicated through the
QWTALK continuum.
Question 7: Will I be able to obtain quick turnaround on QC
samples so I can determine if I am properly applying the
cleaning procedures and other quality-assurance procedures?
Answer: The NWQL is developing a set of Custom Analyses
Schedules for analyzing deionized water blanks. The specifics
are (1) a 2- to 3-week turnaround time; (2) detection levels
in the range of 0.2 to 0.4 ug/L, for 15-20 (actual number to
be determined) trace elements analyzed by ICP/MS, and (3)
analyses of nutrients, major ions, and additional trace
elements (such as arsenic, selenium, mercury) by existing
methods.
The ICP/MS method will be an extension of a proven method that
has reporting levels of 1 5g/L for 15 trace elements. Thus,
the method will be experimental and the QC results will not be
reportable in Annual Data Reports or allowable in NWIS until
the method is approved. The OWQ is extending the method
because QC data which have the same reporting level as
environmental data have very limited value. The target is to
get the reporting level for the QC data below one-half the
reporting level of the environmental data.
The NWQL will distribute a Technical Memorandum on this issue
in August.
Question 8: Our office has a new system for producing deionized
water and initial QC results show that there is no trace-
element contamination. Why should we pay the cost of buying
inorganic-free blank water (IFBW)?
Answer: There are two reasons to buy the IFBW. First, your past
analyses are probably at reporting levels of 1 ug/L for most
trace elements (unless custom analyses were run for specific
analytes). As explained under question 7, this level provides
limited protection against the actual presence of
contamination.
Second, what is the cost of consistent QC on the District
deionized water system, compared to the cost of buying IFBW?
The IFBW is QCed and virtually guaranteed contaminant free at
all times. In contrast, if a District system goes bad, and
QC samples are collected infrequently, all of the
environmental samples collected in the intervening time period
could be contaminated.
Question 9: You talk about collecting and interpreting QC data.
Where can I learn how to interpret the QC data?
Answer: The Branch of Quality Assurance, in cooperation with the
OWQ, will conduct a Workshop on Interpretation, Management,
and Presentation of Water-Quality Quality-Control Data during
November 1-5, 1993, in Denver. At least one person from each
District should attend and later provide training to the other
District personnel.
Question 10: Given the lack of field method identification
capability in NWIS, if different programs and projects begin
using the protocol at different times, future data users will
not know what method was used to collect recorded data.
Therefore, shouldn't all programs and projects begin using the
protocol at the same time?
Answer: The transition to using the protocol represents a
difficult cultural change in how the Division conducts water-
quality work. Some programs and projects are anxious to use
the protocol now (a few already are). Others might not be
ready for a year or more. We are making the stated decision
so as many projects as possible can begin producing good-
quality data as quickly as possible. To continue to produce
poor-quality data or even no data (when good-quality data
could be produced) is unacceptable.
Question 11: What is the bottom line on whether we need to
follow all aspects of the protocol at all times?
Answer: There are four points to consider. First, the protocol
is provided as a guide to improving WRD's data-collection
efforts. The key messages of the protocol are: (1) inorganic
samples can be contaminated, but sources of contamination can
be reduced through proper planning, use of tested equipment/
supplies, proper cleaning, and specified quality-assurance
measures; and (2) collection of adequate QC data will identify
whether problems exist (suggested QC in the protocol should be
considered only a minimum guide to what may be needed to
identify the problems).
Second, the OWQ has data to prove that the protocol works for
trace elements, nutrients, and major ions, provided the
recommended equipment and supplies are used and all cleaning
and other quality-assurance procedures are appropriately
followed.
Third, based on cost, time, and availability of personnel,
situations may arise wherein it would be desirable to ignore
all or parts of the protocol. However, this creates the risk
of contamination and bad data. When shortcuts are taken, the
project must develop the appropriate types and amounts of QC
data to ensure that the changes do not produce contamination
in the results. The types and amounts of QC data required
will depend on (1) the overall objects of the program or
project and (2) the data-quality objectives of each specific
data-collection activity.
Fourth, each deviation from the protocol constitutes an
experiment the District or project must conduct to ensure lack
of contamination. Furthermore, the efficacy of deviating in
multiple procedures or steps constitutes a multistep
experiment because, if the QC data show contamination, each
specific deviation will need to be evaluated separately to
find the source(s).
As more experience is gained using the protocol, modifications
will be made. However, for now consider that parts of the
protocol (e.g., cleaning methods, equipment, supplies) are
relatively easy to apply and much less expensive than poor-
quality data.
The OWQ is implementing the protocol on October 1, 1993, in order
to provide the earliest possible benefit to the Division.
Employment of the procedures contained in the protocol is an
important step to improving data quality for WRD's mission. A
preliminary list of equipment and supplies discussed in the
protocol is attached for informational purposes. Recall that the
OWQ will issue a Technical Memorandum to present the protocol as
Division policy.
David A. Rickert
Chief, Office of Water Quality
Attachment
This memorandum does not supersede any previous Office of Water
Quality Technical Memorandum.
Key Words: field procedures, inorganic, trace elements
Distribution: A, B, S, FO, PO
ATTACHMENT 1
EQUIPMENT AND SUPPLIES REQUIRED FOR INORGANIC PROTOCOL--
SURFACE-WATER SAMPLING
Non-contaminating sampler (DH-81, D-77, Frame)
with polyethylene or Teflon bottle or bag, cap, and nozzle
Churn splitter (8 or 14 L) (Bel-Art Products)
Carrier for churn splitter (plastic container with lid)
Processing and preservation chambers (cpvc or pvc)
Plastic bags, clear for use in chambers
Capsule filters, Supor (Gelman 12175/12176) OR
142mm plate filter and MFS cellulose acetate filters
Non-metallic forceps for handling filters
Peristaltic pump for filtration
Pump tubing (silicon or Teflon)
Non-powdered vinyl gloves, disposable
Liquinox
Concentrated hydrochloric acid (HCl), Baker Instra-Analyzed
Deionized water (DIW)
Tap water
Wash basins, clear plastic
Non-metallic brushes
Wash bottles, safety labeled, for dilute HCl, DIW
Sealable plastic bags (Ziplock) for storing cleaned equipment
Inorganic-free blank water
DH-81 and D-77 samplers are currently available from the Waterways
Experiment Station in Vicksburg, Miss. (Contact Wayne O'Neal,
601-634-2721). Plans for the frame sampler will be available from
the Office of Water Quality. All other equipment and supplies,
except the water, will be available by October 1, 1993, from the
Quality Water Services Unit in Ocala, Fl.
Plans for processing and preservation chambers are available
as Framemaker files. They can be obtained by:
ftp 130.11.51.209
login: anonymous
password: your userid
cd pub
get pros.enc.493.fm/3
get pres.enc.493.fm/1
get proc.enc2.fm/
bye