“Water
is the one substance from which the earth can conceal nothing; it sucks out its
innermost secrets and brings them to our very lips.”
—Jean
Giraudoux
What Comprises
Comprehensive Sampling?
Since the early
’70s, Cobb County, GA’s municipal in-stream monitoring efforts have evolved into
a program that conducts sampling across 21 sub-watersheds at 93 chemical sites
per quarter, 24 macroinvertebrate sites per year, 24 habitat assessment sites
biannually, and 24 fish sites every five years. Sites were selected considering
land use, proximity to industries, and stream confluences of representative
reaches.
The chemical data
generate a water quality index (WQI) score derived from comparing the value for
any parameter of interest with values for the same available parameter from
sampling results recorded throughout the Atlanta region. The index itself is a
value between 0.00 and 1.00, with 0.00 representing the best value in the
database for each parameter. Table 1 shows the Cobb Stream Monitoring Program
chemical data for an actual site with each parameter and applicable scores. The
aggregate WQI for the site is calculated as the numeric average of the available
WQIs shown.
Biological
sampling produces macroinvertebrate and fish data, which are scored on an index
of biotic integrity (IBI). Habitat assessments are scored on a standardized form
following state of Georgia Environmental Protection Division (EPD)
protocol.
A Cobb County
Water System Watershed Monitoring Program Annual Report is published containing
all of the chemical, biological, and habitat data collected; many permits
addressing surface waters impacted by wastewater discharge, stormwater, point
and non-point sources are maintained by the data. In the report, narratives for
each site summarize a year’s worth of changes to the stream channel, riparian
zone, and watershed itself as personnel wade upstream and drive through the
watershed on the way to each site.
How Comprehensive Is
It?
Ions
in the Stream. Chemical
monitoring parameters and methods are long-established water-quality standards
prescribed by the approved 20th edition of Standard
Methods for the Examination of Water and Wastewater (Clesceri et al. 1998) and are implicit in
environmental regulatory sampling like National Pollutant Discharge Elimination
System (NPDES) wet-weather ambient trend monitoring. Cobb County Stream
Monitoring personnel take extra measures to ensure accuracy and integrity. For
example, rather than rely on precarious dissolved oxygen (DO) meter readings,
Winkler titration method dissolved oxygen samples are “fixed” in the field for
more consistent and accurate analysis by Cobb’s Georgia Association of Water
Professionals certified wastewater laboratory. Quality-control samples are
collected at the first site for a given stream, and all samples are collected
mid-depth in representative flow when possible and preserved in the field before
transportation to the laboratory. Field notes supporting chemical sample
characteristics are made concerning weather, degree of flow, color, odor, and
turbidity.
Success
and Struggle; Soft Stomping Dance. Chemical sampling gives an immediate snapshot
of the stream’s overall health, whereas biotic sampling crafts a long-term
tapestry of success and struggle for the stream. A plethora of terrestrial adult
insects spawn and mature in aquatic environments, and the relative numbers of
one group compared with another indicates general trends in water quality for a
site. Macroinvertebrate biotic evaluations are sanctioned in the state of
Georgia Standard Operating Procedures (SOP) protocol and involve sampling in
five distinct stream habitats.
A riffle kick, a
kind of soft stomping dance, is performed in the rocky, high-flow area of a
stream, upstream of a net held on the bottom, jostling insect larvae and nymphs
(incompletely metamorphosing aquatic insect young) into the net. Because high
flows push sediment on and DO is generated by the aeration of water over the
uneven rocks, diverse and demanding (and thus, pollution-intolerant) orders of
macroinvertebrates can be collected, including Megaloptera (dobsonfly) and
Plecoptera (stonefly). Stream colleagues often comment on the physical beauty
and all-too-rare sightings of one of the most sensitive freshwater denizens, the
stonefly.
 |
| Photo: Lanse Norris |
Adam Sukenick and Erin Feichtner, Cobb stream biologists |
Undercut bank and
“root” sampling involves agitating a net under bank roots, or agitating the
roots when net movement is not possible. Riffle insects are also found in roots,
as are Odonata (dragonfly), a somewhat sensitive nymph.
Coarse,
particulate, organic matter (CPOM) and “leaf packs” of decaying matter snagged
in areas of appreciable flow can be collected by hand and often include
Tipulidae (crane fly) as well as stoneflies. The Tipulidae family in the order
Diptera is somewhat sensitive to pollution and contributes toward average
scores.
Large, woody
debris and rocks are scraped with sensitive brushes, and often Trichoptera
(caddisfly) and Ephemeroptera (mayfly) are swept into a collection bucket. Among
caddisflies, classified as either sensitive or somewhat sensitive by Georgia
Adopt-A-Stream (2006), family Hydropsychidae (net spinner) has a relatively high
pollution-tolerance rating. This is probably because it has gills, and
therefore, greater dissolved oxygen exchange surface area, as opposed to
exercising simple cutaneous respiration through the body wall. Also, as a filter
feeder, it can utilize degraded conditions as more suspended algae and
particulate organic matter is generally available. Case-making caddisflies,
family Leptoceridae, are also more tolerant than their gill-less, free-living
cousins in family Rhyacophilidae, as they undulate vigorously within their stone
or wood debris cases, augmenting flow and subsequent DO
absorption.
Sand samples are
collected in a similar manner to riffle kicks, with a shuffling upstream of a
bottom net, taking care not to dredge too much sand. Family Gomphidae (burrowing
dragonfly) and Hexagenia (burrowing mayfly) are often collected. Family
Chironomidae (midge fly) in the order Diptera found here, particularly red
chironomids, are classified as especially tolerant because their hemoglobin
captures more precious dissolved oxygen in degraded conditions than that of
their white chironomid cousins. Non-native mussels in the family Corbiculidae
recovered here are somewhat sensitive according to the Aquatic
Macroinvertebrate Field Guide for Georgia’s Streams (Georgia Adopt-A-Stream 2006), yet are tolerant
of silting conditions. When they are present in large numbers with chironomids
and subclass Oligochaeta (worm), as compared with low numbers for other macros,
we can infer deteriorated water quality, because sensitive and
somewhat-sensitive groups are not well represented.
 |
| Photo: Adam Sukenick |
Norris sampling in riffle-like area of a rock waterfall |
Specimens are
identified to family in the field, and difficult identifications are brought
back to the lab for identification with a microscope and dichotomous key. With
the keys, genus level identification is done for specific watershed studies,
such as those required for permitting wastewater plant expansion. Notations are
made of crawfish sightings as well; crustaceans of the order Decapoda (crayfish)
are somewhat sensitive and are indicators of moderate water-quality
conditions.
Home,
Stream Home, or Home Is Where the Harm Is? In their field notes for each site, stream
personnel scrutinize transforming channel, buffer, and canopy, chronicling
effective eons of scouring flow, scourging drought, and salvaged diversity,
complex long moments in vulnerable watersheds of the developing Southern
Piedmont. Therefore, appreciable comprehension is achieved in-stream sampling
and concomitant habitat assessments. Cobb County
Stream Monitoring personnel follow the Georgia EPD SOP for biological assessment
as well as the US Geological Survey protocol, Methods
for Characterizing Stream Habitat as Part of the National Water Quality
Assessment Program.
Indeed, “habitat
is an inclusive term that includes both shelter and food sources and thus, any
physical structure that may be utilized as such. The Habitat Assessment section
list for sampling and evaluation includes: rocks and riffle run, fallen
trees/large woody debris, deep pools, shallow pools, overhanging shrubbery in
water, large rocks, undercut banks, thick root mats, macrophyte beds, and deep
riffles with lots of turbulence” (Bourne 2003). Also, results from habitat
assessments “determine the ability of the stream to provide stable environment
for macroinvertebrate and fish populations” (Sukenick
2003).
A sheet scoring
each habitat is filled out and evaluated in order to better understand the
aforementioned changes in the ability of a stream to provide stable biotic
environment. Some significances of each habitat scored are detailed
here.
The shallow water
and turbulence of rocky riffles sponsor critical oxygen uptake and release of
toxic gases. Rocks stabilize the stream and provide macroinvertebrate shelter
from velocity for, especially, filter feeders relying on particulate food matter
borne in swift currents. According to Romoser and Steffalano (1998), “Water
currents often determine which species of insects will live in a given area …
mayflies (Ephemeroptera) may be classified into still water or rapid water
forms.” Gravel in these areas provides a breeding ground for many fish
species.
The swift, deeper
currents of runs transport microorganisms and organic particulate matter for
filter-feeder macroinvertebrates.
Exposed roots
from undercut banks provide shelter for macroinvertebrates and fish avoiding
predators and storm event high flows.
Pool habitat
provides slow, deep water for fish and can provide shelter for those migrating
from riffle feeding areas. Lower velocities in depositional pools allow
burrowing organisms to thrive.
Trees and shrubs
are essential to stream ecology as demonstrated in the fibrous mats of roots’
“resilient matrix for attachment and for shelter for … vertebrates and
invertebrates” (Bourne 2003). Leaf packs shelter and provide food for Tipulidae
and other shredders whose discharged waste supports filter feeders downstream
such as Dipteran (black fly) larvae in family Simuliidae as well as
Hydrosychidae. In fact, “Stream ecology
is fundamentally different from lakes and rivers in that CPOM, coarse
particulate organic matter, not algae, is the most important food source”
(Bourne 2003).
Somewhat rare in
Cobb County, macrophytic (or macroscopic) vegetation found in glide pool streams
stabilize sediment, cycle nutrients, and provide habitat when
present.
Fish:
Identification, Please. Cobb
County conducts fish identification and release every five years in each of the
four waste water plants’ service areas. Sampling follows the aforementioned
Georgia protocol, and trained taxonomists identify the fish. Scores for each
site are predicated on some of the following considerations concerning
adaptability for different orders of fish.
 |
| Photo: Travis Neumeuller |
Lanse Norris, Erin Feichtner, and Adam Sukenick assessing
habitat |
Mosquito fish and
topminnows are Cyprinodontiformes, characterized by an upturned mouth and
flattened head. They therefore swim just under the surface, feeding on fallen
organisms and emerging adult insects. They can also take advantage of the
oxygen-rich surface film in otherwise low-DO waters. The mosquito fish, Gambusia
affinis, is tolerant of slow-moving, eutrophic (plant-nutrient-choked) waters
and is thought to control malaria and possibly the West Nile virus borne by
mosquitoes thriving in those conditions.
Minnows,
shiners, suckers, and catfish belong to the super order Ostariophysi and occur
extensively in all sizes of water bodies. Shiners and chubs in the family
Cyprinidae can be specialized,
requiring (and, therefore, good indicators of) desirable diverse habitat and
macroinvertebrate populations.
Bass, sunfish,
perch, and sculpins, the “percomorph” fishes, are found throughout Cobb County.
Perch darters, in the family Percidae, of which the threatened Cherokee darter
is a member, have adapted to use pectoral and pelvic fins like limbs as they
stalk prey. The banded sculpin, Cottus carolinae, is particular about and a
strong indicator of superior, rocky habitat and is “also reported to avoid
lowland areas and turbid waters” (Wallus and Simon 2006).
Stream Monitoring
personnel are trained in other disciplines relating to freshwater, including
stream morphology and hydrology, riparian botany, ecology, soils, and
construction erosion and sediment control measures.
Why Comprehensive
Sampling?
“Water
is a very good servant, but it is a cruel master.”—C.G.D. Roberts,
Adrift
in America,
1891
I could almost
stop with this quotation, and some probably wish I would.
Dave Rosgen (1996)
says “A number of United States government agencies [including] the
Environmental Protection Agency, USDA Forest Service, Natural Resources
Conservation Service, US Army Corps of Engineers, and the Bureau of Land
Management are engaged in a process of developing river design criteria and new
management standards and guidelines related to resource values associated with
rivers, riparian, and watershed areas.”
The short related
answer for Cobb Water System Management is that, as regulations have evolved,
the Cobb Stream Monitoring Program has covered, and indeed anticipated, new and
more comprehensive regulations, including sampling aspects of Cobb’s Noonday
Creek and other expanding wastewater reclamation facilities’ NPDES permits.
Cobb’s program also supports Stormwater Management’s NPDES water-quality
monitoring plan; NPDES fecal
geometric mean sampling; MS4 Atlanta Metropolitan North Georgia Water Planning
District biota sampling in HUC 12s; 303(d) list total maximum daily load (TMDL)
sampling for metals, fecals, biota, and other parameters; as well as NPDES Phase
I education requirements through Cobb Adopt-A-Stream. Stream Monitoring also
supports Cobb Water System’s Capacity Management, Operation and Maintenance
program sampling. Early in the history of the program, Stream Monitoring was
instrumental in regulating, permitting, and closing some point sources
discharging to waterways, and, in that way, dealt with its past as well as
future.
So, considering
the obvious point that municipalities never want to run afoul of regulators with
direct permit oversight, environmental and general practicality can drive more
intense sampling efforts as well. Because Cobb County is situated in the
ecologically diverse inner Piedmont (USGS 2001), freshwater stakeholders share
an especial sensitivity to anthropogenic pressures, ranging from
impervious-surface-flow-sponsored stream bank erosion and thermal pollution to
nonpoint-source pollution from vehicles, pets, and construction sites—things
unwelcome in communities of invertebrates and vertebrates adapted to retain
attorneys. As John Thorson, an author and attorney who deals extensively with
water policy, has said, “Water links us to our neighbor in a way more profound
and complex than any other.”
An anecdote
illustrating unanticipated benefits of in-stream sampling demonstrates the
acquired expertise of stream personnel and the high degree of interdepartmental
coordination fostered by centralized stream monitoring and reporting. This
example involves Adam Sukenick, Cobb County stream biologist, and I attempting
to discern the source of a mysterious milky substance in 2002.
Stormwater
Management and Stream Monitoring’s mutual support policy at that time involved
Stormwater Management gathering approximately one-third of the chemical samples
for a given stream, so when Stormwater Management discovered the illicit flow at
one of its sites, the “stream team” was contacted in the field at one of their
sites to break off and render their keener expertise in the identification of
the substance and its source. Because Stream Monitoring GIS data delineate
perennial streams in the county, and the flow was characteristic of a distinct
light clay layer often disturbed in construction, Sukenick quickly discerned
that the substance was flowing from a nondelineated section of newly diverted
stream, probably from a construction site. Having traced the material to a
construction site in the burgeoning Vinings area of Cobb County, and being
skilled in the steps of best compliance practices, Sukenick and I then contacted
Stormwater Management senior engineer Henry Mingledorff who produced plan review
documents of the site where the developer had actually obscured the original
stream on the topographical map in order to divert attention from his, well,
diversion of the stream. Because Cobb Stream Monitoring is central to so many
permits administered in the county, Sukenick enjoyed a direct relationship with
Cobb’s Community Development division manager and was able to expedite a
stop-work order on the site, expediting the reinstatement of a “blueline”
perennial stream, not to mention the establishment of corrective BMPs obviating
the illicit flow. It is problematic to consider how much slower and more awkward
the process would have been, and if it would have occurred at all, without
Stream Monitoring in the field in the first place, with a high degree of
observational, diagnostic, and interdepartmental wherewithal.
Why Ask
Why?
So, as we ask the question “why should municipalities
attempt comprehensive
in-stream monitoring?” the answer can be as simple as revising the question: Why
wouldn’t they, considering that it assimilates into already-established,
required sampling programs, enhancing them in gratifyingly comprehensive ways?
Why wouldn’t permittees attempt as much ownership of their programs as possible,
when the nature of in-stream sampling puts them in the control tower of civic,
private, regulatory, and environmental traffic? Or, to evoke a different
metaphor, in a world where municipalities struggle to maintain control and
sovereignty over their kingdoms of contending civic, private, regulatory, and
environmental forces, comprehensive in-stream monitoring can
be the jewel in the crown of accountability.