[Federal Register Volume 60, Number 107 (Monday, June 5, 1995)]
[Proposed Rules]
[Pages 29537-29543]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-13457]



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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AD28


Endangered and Threatened Wildlife and Plants; Proposal To List 
Three Aquatic Invertebrates in Comal and Hays Counties, Texas, as 
Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: The Fish and Wildlife Service proposes to list three aquatic 
invertebrate species known only from Comal and Hays counties, Texas, as 
endangered species under the Endangered Species Act of 1973, as amended 
(Act). The primary threat to these species is a decrease in water 
quantity and quality as a result of water withdrawal and other 
activities by humans throughout the San Antonio segment of the Edwards 
Aquifer. This proposal, if made final, will implement Federal 
protection provided by the Act for the Peck's cave amphipod 
(Stygobromus pecki), Comal Springs riffle beetle (Heterelmis 
comalensis), and Comal Springs dryopid beetle (Stygoparnus comalensis).

DATES: Comments from all interested parties must be received by August 
4, 1995. Public hearing requests must be received by July 20, 1995.

ADDRESSES: Comments and materials concerning this proposal should be 
sent to the State Administrator, U.S. Fish and Wildlife Service, 10711 
Burnet Road, Suite 200, Austin, Texas 78758. Comments and materials 
received will be available for public inspection, by appointment, 
during normal business hours at the above address.

FOR FURTHER INFORMATION CONTACT: Ruth Stanford, Ecologist, or Alisa 
Shull, Fish and Wildlife Biologist (see ADDRESSES section) (512/490-
0057).

SUPPLEMENTARY INFORMATION:

Background

    The U.S. Fish and Wildlife Service (Service) proposes to list as 
endangered under the Endangered Species Act of 1973, as amended (Act) 
three aquatic invertebrate animal species with a known distribution in 
spring sites in Comal and Hays counties, Texas; two of the species are 
subterranean. Peck's cave amphipod is known from Comal Springs and 
Hueco Springs, both in Comal County. The Comal Springs riffle beetle is 
known from Comal Springs and San Marcos Springs (Hays County). The 
Comal Springs dryopid beetle is known from Comal Springs and Fern Bank 
Springs (Hays County). The water flowing out of each of these springs 
comes from the Edwards Aquifer (Balcones Fault Zone--San Antonio 
Region), which extends from Hays County on the east to Kinney County on 
the west. Comal Springs are located in Landa Park, which is owned and 
operated by the City of New Braunfels, and on private property adjacent 
to Landa Park. Hueco Springs and Fern Bank Springs are located on 
private property. San Marcos Springs are located on the property of 
Aquarena Springs, formerly a privately owned resort facility. Southwest 
Texas State University purchased the facility in 1994. Aquarena Springs 
continues to operate as a resort, but the university plans to increase 
conference facilities and provide educational and interpretive displays 
and to increase availability of the springs for biological and 
ecological research (Billy Moore, Public Affairs Director, Southwest 
Texas State University, pers. comm., 1995).
    Peck's cave amphipod is a subterranean, aquatic crustacean. The 
other two species are aquatic beetles. The families to which these 
beetles belong live primarily in flowing, uncontaminated waters. The 
Comal Springs riffle beetle is a surface species in the family Elmidae. 
The Comal Springs dryopid beetle is the only known subterranean member 
of the family Dryopidae.
    The first recorded specimen of the amphipod Stygobromus 
(=Stygonectes) pecki (Holsinger 1967) was collected by Peck at Comal 
Springs in June, 1964. Reddell collected a second specimen at the same 
place in May, 1965. In 1967, Holsinger named the species Stygonectes 
pecki, in Peck's honor; the 1965 specimen, an adult female 10.5 mm 
(about one half inch) long, served as the type specimen. Later he 
included all the nominal Stygonectes species in the synonymy of the 
large genus Stygobromus. The Service has used ``cave amphipod'' as a 
generic common name for members of this genus, and this name was simply 
translated as ``Peck's cave amphipod'' without reference to a 
particular cave. Other known springs and artesian wells of the Edwards 
Aquifer in central Texas have been extensively sampled for amphipod 
crustaceans; a single specimen of Peck's cave amphipod was collected at 
Hueco Springs by Barr in August, 1992.
    Over 300 specimens of Peck's cave amphipod have been collected 
since its description. Most documented specimens were netted from 
crevices in rock and gravel near the orifices of the three largest 
Comal Springs on the west side of Landa Park in Comal County, Texas. 
Barr collected one specimen from a fourth Comal spring run on private 
property adjacent to Landa Park and one specimen from Hueco Springs, 
about 7 km (4 miles) north of Comal Springs (Barr 1993). However, like 
all members of the exclusively subterranean genus Stygobromus, this 
species is eyeless and unpigmented, indicating that its primary habitat 
is a zone of permanent darkness in the underground aquifer feeding the 
springs. Above ground, individuals are easy prey for predators, but 
they usually take shelter in the rock and gravel crevices and may 
succeed in reentering the spring orifice. Barr (1993) got most 
specimens in drift nets at spring orifices and found them less often as 
she moved downstream, supporting the notion that they may be easy prey 
and do not likely survive for long outside the aquifer.
    The Comal Springs riffle beetle is a small, aquatic beetle known 
from Comal Springs and San Marcos Springs. It was first collected by 
Bosse in 1976 and was described in 1988 by Bosse et al. The closest 
relative of H. comalensis appears to be a species that occurs farther 
to the west (Bosse et al. 1988).
    Adult Comal Springs riffle beetles are about 2 mm (\1/10\ inch) 
long, with females slightly larger than males. Unlike the other two 
organisms proposed here, the Comal Springs riffle beetle is not a 
subterranean species. It occurs in the gravel substrate and shallow 
riffles in spring runs. Some riffle beetle species can fly, but the 
hind wings of Heterelmis comalensis are short and almost certainly non-
functional, making the species [[Page 29538]] incapable of this mode of 
dispersal (Bosse et al. 1988). The larvae have been collected with 
adults in the gravel substrate of the spring headwaters and not on 
submerged wood as is typical of most Heterelmis species (Brown and Barr 
1988). Usual water depth in occupied habitat is 2 to 10 cm (1 to 4 
inches) although the beetle may also occur in slightly deeper areas 
within the spring runs. Populations are reported to reach their 
greatest densities from February to April (Bosse et al. 1988). The 
Comal Springs riffle beetle has been collected from spring runs 1, 2, 
and 3 at Comal Springs in Landa Park, and a single specimen was 
collected from San Marcos Springs 32 km (20 miles) to the northeast.
    The Comal Springs dryopid beetle is a recently discovered species. 
It was first collected in 1987 and described as a new genus and species 
in 1992 by Barr (California State University) and Spangler (National 
Museum of Natural History, Smithsonian Institution). Adult Comal 
Springs dryopid beetles are about 3.0-3.7 mm (\1/8\ inch) long. They 
have vestigial (non-functional) eyes and are weakly pigmented, 
translucent, and thin-skinned. The species is the first stygobiontic 
(subterranean aquatic) member of its family to be discovered (Brown and 
Barr 1988, Barr, in litt. 1990, Barr and Spangler 1992). Collection 
records for the Comal Springs dryopid beetle are primarily from spring 
run 2 at Comal Springs, but they have also been collected from runs 3 
and 4 at Comal Springs and from Fern Bank Springs about 32 km (20 
miles) to the northeast in Hays County. Specimens have been collected 
in April, May, June, July, and August. Most of the specimens have been 
taken from drift nets or from inside the spring orifices. Although the 
larvae of the Comal Springs dryopid beetle have been collected in drift 
nets positioned over the spring openings, they are presumed to be 
associated with air-filled voids inside the spring orifices since all 
other known dryopid beetle larvae are terrestrial. Unlike Peck's cave 
amphipod, the Comal Springs dryopid beetle does not swim, and it may 
have a smaller range within the aquifer.
    The exact depth and subterranean extent of the ranges of the two 
subterranean species (Comal Springs dryopid beetle and Peck's cave 
amphipod) are not precisely known because of a lack of methodologies 
available for studying karst aquifer systems and the organisms that 
inhabit such systems. The subterranean portion of this habitat may be a 
single, interconnected system that provides the area necessary for the 
feeding, growth, survival, and reproduction of the Comal Springs 
dryopid beetle and Peck's cave amphipod, which are obligate aquatic 
stygobiontic species. However, no specimens of Stygoparnus comalensis 
or Stygobromus pecki have appeared in collections from 22 artesian and 
pumped wells flowing from the Edwards Aquifer (Barr 1993), suggesting 
that these species may be confined to small areas surrounding the 
spring openings and are not distributed throughout the aquifer. Barr 
(1993) also surveyed nine springs in Bexar, Comal, and Hays counties 
considered most likely to provide habitat for endemic invertebrates and 
found Stygoparnus comalensis only at Comal and Fern Bank springs and 
Stygobromus pecki only at Comal and Hueco springs.
    The low water limits for survival are not known for any of these 
three invertebrate species. At least a single population of each 
species survived the drought of the middle 1950's, which resulted in 
cessation of flow at Comal Springs from June 13 through November 3, 
1956. Hueco springs is documented to have gone dry in the past (Brune 
1981; Barr 1993), and although no information is available for Fern 
Bank Springs, it has probably gone dry as well given its higher 
elevation (Glenn Longley, Edwards Aquifer Research and Data Center, 
pers. comm., 1993). San Marcos Springs has not gone dry in recorded 
history.
    Although these invertebrates were not entirely extirpated by the 
temporary cessation of spring flow, they may have been adversely 
affected and are not expected to be able to survive long periods of 
drying (up to several years in duration) that may occur in the absence 
of an adequate water management plan for the Edwards Aquifer. 
Stagnation of water may be a limiting condition, particularly for the 
two stygobiontic invertebrates. Stagnation of water and/or drying 
within the spring runs and the photic (lighted) zone of the spring 
orifices would probably be limiting for the Comal Springs riffle 
beetle. Natural water flow is considered important to the respiration 
and therefore survival of these species. The two beetle species have a 
mass of tiny, hydrophobic (unwettable) hairs on their underside where 
they maintain a thin bubble of air through which gas exchange occurs 
(Chapman 1982). This method of respiration loses its effectiveness as 
the level of dissolved oxygen in the water decreases. A number of 
aquatic insects that use dissolved oxygen rely on flowing water to 
obtain oxygen from the water.
    In a petition dated September 9, 1974, the Conservation Committee 
of the National Speleological Society requested the Service to list 
Peck's cave amphipod. The species was included in a notice of review 
published on April 28, 1975 (40 FR 18476). A ``warranted but 
precluded'' finding regarding several species in that petition was made 
October 12, 1983, and published January 20, 1984 (49 FR 2485). The same 
petition determination has been repeated for Peck's cave amphipod in 
subsequent years. The species was included as a category 2 candidate in 
comprehensive notices of review published May 22, 1984 (49 FR 21664), 
January 6, 1989 (54 FR 554), and November 21, 1991 (56 FR 58804). In 
the latest notice of review of November 15, 1994 (59 FR 58982), it was 
included as a category 1 candidate.
    In a petition dated June 20, 1990, and received June 21, 1990, Mr. 
David Whatley, Director of the City of New Braunfels Parks and 
Recreation Department, requested the Service to list five invertebrate 
taxa, including Peck's cave amphipod and four insects. The Service 
treated this as a second petition for the amphipod. A notice of 90-day 
petition finding published April 29, 1991 (56 FR 19632) announced that 
the petition had presented substantial information indicating that 
listing the Comal Springs riffle beetle and the Comal Springs dryopid 
beetle may be warranted, and initiated a formal status review for those 
species. Taxonomic uncertainties about the Comal Springs Microcylloepus 
riffle beetle and Hexagenia mayfly, also included in the June 21, 1990, 
petition, led to 90-day petition findings that were negative for those 
insects. The Heterelmis was recognized as a category 2 candidate in the 
November 21, 1989, notice of review, and both it and the Stygoparnus 
were recognized as category 1 candidates in the 1994 notice of review.
    The present proposal constitutes a positive 1-year finding for the 
petitions to list the Comal Springs riffle beetle, Comal Springs 
dryopid beetle, and Peck's cave amphipod.

Summary of Factors Affecting the Species

    Section 4(a)(1) of the Endangered Species Act (16 U.S.C. 1531 et 
seq.) and regulations promulgated to implement the listing provisions 
of the Act (50 CFR Part 424) set forth the procedures for adding 
species to the Federal lists. A species may be determined to be an 
endangered or threatened species due to one or more of the five factors 
described in Section 4(a)(1). These factors and their application to 
the Peck's cave amphipod (Stygobromus pecki), Comal Springs riffle 
beetle (Heterelmis comalensis), and Comal Springs dryopid 
[[Page 29539]] beetle (Stygoparnus comalensis) are as follows:
    A. The present or threatened destruction, modification, or 
curtailment of their habitat or range. The main threat to the habitat 
of these aquatic invertebrates is a reduction or loss of water of 
adequate quantity and quality, due primarily to human withdrawal of 
water from the Edwards Aquifer and other activities. Total withdrawal 
from the San Antonio region of the Edwards Aquifer has been increasing 
since at least 1934, when the total well discharge was 101,900 acre-
feet (Edwards Underground Water District 1989). In 1989, the total well 
discharge was slightly more than 542,000 acre-feet (Longley 1991; 
Edwards Underground Water District 1992a).
    There is an integral connection between the waters in the aquifer 
west of the springs and the waters serving as habitat for these species 
at the springs. Water entering the Edwards Aquifer as far west as 
Kinney County would eventually exit at springs were it not for 
withdrawal of groundwater from wells. Water in the Edwards Aquifer 
flows from west to east or northeast, and withdrawal or contamination 
of water in the western part of the aquifer can have a direct effect on 
the quantity and quality of water flowing toward the springs and at the 
spring openings.
    Prior to wells being drilled into the aquifer, the average 
springflow from Comal and San Marcos springs was equal to the average 
annual recharge. That is, almost all of the water entering the aquifer 
eventually exited at the springs. At present, much of the recharge is 
pumped out of the aquifer, and most of what is left becomes the average 
springflow (Guadalupe-Blanco River Authority 1988). The amount of water 
removed by wells is therefore a direct, one-for-one depletion of water 
that would otherwise exit through the springs (Guadalupe-Blanco River 
Authority 1988) and provide habitat for the proposed invertebrates.
    The Texas Water Commission (TWC) (1989) classified the San Antonio 
segment of the Edwards Aquifer as a critical area in terms of its 
potential for groundwater problems related to overdrafting. The 
Commission also ranked Bexar, Comal, and Hays counties among the top 23 
counties in Texas for number of active groundwater public supply 
systems. Human population in the region is expected to increase 
(Technical Advisory Panel 1990; Edwards Underground Water District 
1993), which will result in increased demand for water from the 
aquifer.
    The Texas Water Development Board has applied its model of the 
Edwards Aquifer to determine the maximum pumping level that would allow 
Comal Springs to continue to flow (Technical Advisory Panel 1990). The 
Board found that during a drought similar to that of the 1950's, the 
maximum pumpage that would allow spring flow at Comal Springs is about 
250,000 acre-feet per year (less than half the current pumping rate). 
``At this pumping level, Comal Springs could be expected to maintain 
some annual flow although they may flow on an intermittent basis during 
a recurrence of the drought of record'' (Technical Advisory Panel 
1990). The Panel also stated that in the year 2000, if pumping 
continues to grow at historical rates and a drought of record were to 
occur, Comal Springs would go dry for a number of years (Technical 
Advisory Panel 1990). Wanakule (1990) states: ``The present problem 
facing the Edwards Aquifer is the threat of overdrafting of the annual 
average recharge rate (1934-1988) of approximately 635,500 acre-feet. 
McKinney and Watkins (1993) evaluated the Texas Water Development Board 
model and other models and concluded that, without limiting withdrawal 
to about 200,000 acre-feet per year, Comal Springs will likely go dry 
for extended periods during even a minor drought. The creation of the 
Edwards Aquifer Authority may help to alleviate this threat to some 
degree (see Factor D for further discussion). The Edwards Aquifer 
Authority is currently subject to litigation regarding violation of the 
Voting Rights Act in its formation. The Texas Legislature is now 
considering bills designed to bring the Authority into compliance, but 
the outcome of this effort remains to be determined.
    In 1984 and 1990, some of the higher-elevation Comal Springs ceased 
flowing and water levels in the index well (J-17) in San Antonio 
dropped to within twelve feet of the historic low of 612.5 ft that 
occurred in 1956 (Wanakule 1990). Because these invertebrates require 
relatively well-oxygenated water, a reduction or cessation of spring 
flows, even if standing water remained around the spring orifices, may 
adversely affect the species. Loss of water entirely within their 
habitat would result in the extirpation of these aquatic species from 
their native habitat.
    In addition to a loss of water, a decrease in the water level in 
the aquifer could lead to a decreased quality of water at the springs. 
The Balcones Fault Zone--San Antonio Region is bounded on the south and 
east by a ``bad water'' line across which the groundwater quality 
abruptly deteriorates to greater than 1000 mg/l total dissolved solids 
(TDS). In other words, at the bad water line, there is a transition in 
groundwater from fresh to saline or brackish. Lowered water levels 
resulting from groundwater pumpage or decreased recharge may result in 
deterioration of water quality in the fresh water section of the 
aquifer through movement of the bad water line. The Comal and San 
Marcos Springs are very close to the bad water line (TWC 1989; Edwards 
Underground Water District 1992b) and although the data are 
inconclusive at present, these springs may be sensitive to intrusion of 
saline waters at low aquifer levels. Other possible effects of reduced 
springflow levels include changes in the chemical composition of the 
water in the aquifer and at the springs, a decrease in current velocity 
and corresponding increase in siltation, and increase in temperature 
and temperature fluctuations in the aquatic habitat (McKinney and 
Watkins 1993).
    Another threat to the habitat of these species is the potential for 
groundwater contamination. Pollutants of concern include those 
associated with human sewage (particularly septic tanks), animal/
feedlot waste, agricultural chemicals (especially insecticides, 
herbicides, and fertilizers) and urban runoff (including pesticides, 
fertilizers, and detergents). Pipeline, highway, and railway 
transportation of potentially harmful materials in the Edwards Aquifer 
recharge zone and its watershed with the attendant possibility of 
accidents presents a particular risk to water quality in Comal and San 
Marcos springs. Comal and San Marcos springs are both located in highly 
urbanized areas. Hueco Springs is located alongside River Road, which 
is heavily travelled for recreation on the Guadalupe River, and may be 
susceptible to road runoff and spills related to traffic. Fern Bank 
Springs is in a relatively remote, rural location and its principal 
vulnerability is probably to contaminants associated with leaking 
septic tanks, animal/feedlot wastes, and agricultural chemicals.
    Of the counties containing portions of the San Antonio segment of 
the Edwards Aquifer, the potential for acute, catastrophic 
contamination of the aquifer is greatest in Bexar, Hays, and Comal 
counties because of the higher density of urbanization compared to the 
western counties. Although spill or contamination events that could 
affect water quality may occur to the west of Bexar County, dilution 
and the time required for the water to reach the springs may lessen the 
threat from that area. As aquifer levels decrease, 
[[Page 29540]] however, dilution of contaminants moving through the 
aquifer may also decrease.
    The TWC reported that in 1988 within the San Antonio segment of the 
Edwards Aquifer, Bexar, Hays, and Comal counties had the greatest 
number of land-based oil and chemical spills in central Texas that 
affect surface and/or groundwater with 28, 6, and 4 spills, 
respectively (TWC 1989). As of July, 1988, Bexar County had between 26 
and 50 confirmed leaking underground storage tanks, Hays County had 
between 6 and 10, and Comal County had between 2 and 5 (TWC 1989), 
putting these counties among the top five counties in central Texas for 
confirmed underground storage tank leaks. The TWC estimates that, on 
average, every leaking underground storage tank will leak about 500 
gallons per year of contaminants before the leak is detected. These 
tanks are considered one of the most significant sources of groundwater 
contamination in the State (TWC 1989).
    A TWC project, using the DRASTIC methodology/tool (Aller, et al. 
1987) classified Texas aquifers statewide according to their pollution 
potential. The Edwards Aquifer (Balcones Fault Zone--Austin and San 
Antonio Regions) was ranked among the highest in pollution potential of 
all major Texas aquifers (TWC 1989). The project's objective was to 
identify areas sensitive to groundwater pollution from a contaminated 
land surface. The project modelled both point source and non-point 
source types of contamination. The area of particular concern is the 
Edwards Aquifer recharge zone and its watershed. The TWC (1989) also 
reviewed and reported on the risk to Texas aquifers from sanitary 
landfills, hazardous waste disposal facilities, industrial waste and 
sewage disposal wells, commercial feedlots, and graveyards.
    The DRASTIC methodology may underestimate the importance of faults 
and fractures, which affect the movement of groundwater and pollutants. 
Faults and fractures may act as conduits and/or barriers to groundwater 
flow and, in the vicinity of springs, could facilitate movement of 
contaminants. The Comal Springs fault facilitates the movement of 
groundwater (and potentially pollutants) towards Comal Springs. Hueco 
Springs has a large local recharge component (Brune 1981) and may be 
more susceptible to contamination via polluted runoff than Comal or San 
Marcos Springs. Little information is available on the relative 
contribution of groundwater and local recharge to the water emerging at 
Fern Bank Springs, although the temporary increase in discharge seen 
after storm events indicates a local recharge component (Barr 1993).
    B. Overutilization for commercial, recreational, scientific or 
educational purposes. No threat from overutilization of these species 
is known to exist.
    C. Disease or predation. While individuals of these three species 
may be preyed upon by various predatory insects or fishes, no 
information indicates that this is a substantial threat to any of the 
three species.
    D. The inadequacy of existing regulatory mechanisms. Invertebrates 
are not included on the Texas Parks and Wildlife Department's (TPWD) 
list of threatened and endangered species and are provided no 
protection by the State. Nor do the TPWD regulations contain provisions 
for protecting habitat of any listed species.
    Traditionally, the State of Texas has had no authority to regulate 
withdrawal of groundwater from an aquifer. In response to a lawsuit 
filed against the Service by the Sierra Club (Sierra Club v. Babbitt, 
formerly Sierra Club v. Lujan), the Texas State Legislature passed a 
bill (S.B. 1477) authorizing the creation of the Edwards Aquifer 
Authority (Authority) and granting the Authority the power to regulate 
groundwater withdrawal from the Edwards Aquifer. The bill recommends 
limiting groundwater withdrawal from the aquifer to 450,000 acre-feet 
per year initially, then reducing it to 400,000 acre-feet per year by 
January 1, 2008, based on a model developed by the TWC. One stated goal 
of the bill is to provide continuous minimum springflow of at least 100 
cfs at Comal and San Marcos Springs by the year 2012 to protect species 
that are designated as threatened or endangered under Federal or State 
law. However, some researchers have maintained that, even with such 
pumping limits, flow at Comal Springs will drop below 100 cfs, and the 
springs will likely go dry for extended periods in time of severe 
drought and probably during minor droughts (McKinney and Watkins 1993).
    The bill creating the Authority gives consideration in setting 
minimum springflow requirements only to those species protected under 
Federal or State law. These invertebrates would receive no 
consideration under the current plan until they are listed. In 
addition, Comal and San Marcos Springs are the lowest elevation springs 
in which these invertebrates are found, and maintaining flow at Fern 
Bank and Hueco Springs is not a stated goal of the water withdrawal 
limitations. Efforts to maintain minimum springflow at Comal and San 
Marcos Springs would not necessarily be sufficient to maintain flow at 
Hueco and Fern Bank Springs, which lie at higher elevations.
    Although creation of the Edwards Aquifer Authority and development 
of regulations for limiting withdrawal of groundwater from the Edwards 
Aquifer is a positive step toward protecting the Comal and San Marcos 
spring ecosystems, creation of the Authority is currently a matter in 
litigation regarding compliance with the Voting Rights Act. It is 
uncertain if or when the Authority will be empowered to enforce the 
pumping limits dictated by the legislation, and thus whether it will be 
able to protect these aquatic invertebrates and other threatened and 
endangered species dependent upon water from the aquifer.
    The major regulations affecting water quality in the San Antonio 
segment of the Edwards Aquifer are the Edwards Rules (31 Texas 
Administrative Code, Chapter 313), promulgated and enforced by the TWC 
(recently renamed as the Texas Natural Resource Conservation 
Commission). The Edwards Rules regulate construction-related activities 
on the recharge zone that may ``alter or disturb the topographic, 
geologic, or existing recharge characteristics of the site'' as well as 
any other activity ``which may pose a potential for contaminating the 
Edwards Aquifer.'' The Edwards Rules regulate construction activities 
through review of Water Pollution Abatement Plans (WPAPs). The WPAPs do 
not require site-specific water quality performance standards for 
developments over the recharge zone nor do they address land use or 
impervious cover limitations. The WPAPs do not regulate activities in 
the aquifer contributing zone and, as yet, the Edwards Rules do not 
include a comprehensive plan to address the effects of cumulative 
impacts on water quality in the aquifer (Edwards Underground Water 
District 1993).
    E. Other natural or manmade factors affecting its continued 
existence. The effect of droughts in south central Texas will be much 
more severe than previously was the case, due to the large increase in 
groundwater withdrawals (Wanakule 1990). These species' very limited 
habitat is likely to be lost through drying or decreased volume of 
springflow during minor or severe drought.
    At present, competition is not known to be a significant threat to 
these species. However, two exotic snail species, Thiara granifera and 
Thiara tuberculata are common in the spring runs and, as grazers, may 
compete for food. Another exotic, the giant ramshorn 
[[Page 29541]] snail (Marisa cornuarietis), is present in two of the 
spring runs and may colonize the other runs at low flow levels or 
through transfer by humans.
    The Service has carefully assessed the best scientific and 
commercial information available regarding the past, present, and 
future threats faced by these species in determining to propose this 
rule. Based on this evaluation the preferred action is to list the 
Peck's cave amphipod (Stygobromus pecki), Comal Springs riffle beetle 
(Heterelmis comalensis), and Comal Springs dryopid beetle as 
endangered.
Critical Habitat

    Critical habitat is defined by Section 3 of the Act as-- (i) the 
specific areas within the geographical area occupied by a species, at 
the time it is listed in accordance with the Act, on which are found 
those physical or biological features (I) essential to the conservation 
of the species and (II) that may require special management 
considerations or protection; and (ii) specific areas outside the 
geographical area occupied by a species at the time it is listed, upon 
a determination that such areas are essential for the conservation of 
the species. ``Conservation'' means the use of all methods and 
procedures needed to bring the species to the point at which listing 
under the Act is no longer necessary.
    Section 4(a)(3) of the Act, as amended, and implementing 
regulations (50 CFR 424.12) require that to the maximum extent prudent 
and determinable, the Secretary designate critical habitat at the time 
a species is determined to be endangered or threatened. The Service 
finds that designation of critical habitat is not prudent for Peck's 
cave amphipod, the Comal Springs riffle beetle, and the Comal Springs 
dryopid beetle at this time. Service regulations (50 CFR 424.12(a)(1) 
state that designation of critical habitat is not prudent when one or 
both of the following situations exist-- (1) The species is threatened 
by taking or other human activity, and identification of critical 
habitat can be expected to increase the degree of threat to the 
species, or (2) such designation of critical habitat would not be 
beneficial to the species.
    The Service finds that designation of critical habitat for these 
three species would not be prudent because it would not provide a 
conservation benefit to them, and would actually be detrimental by 
suggesting a misleadingly restricted view of their conservation needs.
    Designation of critical habitat would not be beneficial to these 
species beyond the benefits provided by listing and the subsequent 
evaluation of activities under section 7 of the Act for possible 
jeopardy. In the Service's section 7 regulations at 50 CFR Part 402, 
the definition of ``jeopardize the continued existence of'' includes 
``to reduce appreciably the likelihood of both the survival and 
recovery of the listed species,'' and ``adverse modification'' is 
defined as ``a direct or indirect alteration that appreciably 
diminishes the value of critical habitat for both the survival and 
recovery of a listed species.'' Because these species are endemic to 
such highly localized areas, actions that apparently diminish water 
quality and quantity at the springs would be fully evaluated for their 
effects on the three species through analysis of whether the actions 
would be likely to jeopardize their continued existence. Any action 
that would appreciably diminish the value, in quality or quantity, of 
spring flows on which they depend would also reduce appreciably the 
likelihood of survival and recovery of the three species. The analysis 
for possible jeopardy applied to these species would therefore be 
identical to the section 7 analysis for determining adverse 
modification or destruction of critical habitat; no distinction between 
jeopardy and adverse modification for activities impacting the springs 
on which these species depend can be made at this time. Application of 
section 7 relative to critical habitat would therefore not add 
measurable protection to these species beyond what is achievable 
through review for jeopardy.
    Designation of the springs and their immediate environment as 
critical habitat would actually be detrimental to conservation efforts 
for these species because it would promote the misconception that the 
springs are the only areas important to their conservation. 
Conservation efforts for these species must address a wide variety of 
federally funded or authorized activities (summarized in the 
``Available Conservation Measures'' section of this proposed rule) that 
affect the quality and quantity of water available to these species 
through effects on the recharge sources and aquifer that supply water 
to their habitats. Nearly all of these activities will occur beyond the 
immediate vicinity of the springs, and some will occur many miles away. 
Designation of the springs as critical habitat would be misleading in 
implying to Federal agencies whose activities may affect these species 
that the Service's concern is limited only to activities taking place 
at the springs occupied by the species. Designation of critical habitat 
for these species would therefore not be prudent.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened under the Endangered Species Act include recognition, 
recovery actions, requirements for Federal protection, and prohibitions 
against certain practices. Recognition through listing encourages and 
results in conservation actions by Federal, State, and private 
agencies, groups, and individuals. The Endangered Species Act provides 
for cooperation with the States and requires that recovery actions be 
carried out for all listed species. The protection required of Federal 
agencies and the prohibitions against taking and harm are discussed, in 
part, below.
    Conservation and management of the Peck's cave amphipod, Comal 
Springs riffle beetle, and Comal Springs dryopid beetle are likely to 
involve protection and conservation of the Edwards Aquifer and spring 
flow at Comal Springs, Hueco Springs, San Marcos Springs, and Fern Bank 
Springs. It is also anticipated that listing will encourage research on 
critical aspects of the species' population biology.
    Section 7(a) of the Act, as amended, requires Federal agencies to 
evaluate their actions with respect to any species that is proposed or 
listed as endangered or threatened and with respect to its critical 
habitat, if any is being designated. Regulations implementing this 
interagency cooperation provision of the Act are codified at 50 CFR 
Part 402. Section 7(a)(4) requires Federal agencies to confer 
informally with the Service on any action that is likely to jeopardize 
the continued existence of a proposed species. If a species is listed 
subsequently, Section 7(a)(2) requires Federal agencies to ensure that 
activities they authorize, fund, or carry out are not likely to 
jeopardize the continued existence of such species or to destroy or 
adversely modify its critical habitat. If a Federal action may affect a 
listed species or its critical habitat, the responsible Federal agency 
must enter into formal consultation with the Service. Federal actions 
that could affect the Peck's cave amphipod, Comal Springs riffle 
beetle, and/or Comal Springs dryopid beetle include the funding, 
authorization, and implementation of projects that would reduce the 
quantity or quality of water within the San Antonio segment of the 
Edwards Aquifer or otherwise significantly affect the outlets or water 
output of Comal Springs in New Braunfels, Texas; San Marcos Springs in 
[[Page 29542]] San Marcos, Texas; Hueco Springs in Comal County, Texas; 
and Fern Bank Springs in Hays County, Texas. Examples of these types of 
activities include projects that would involve withdrawal of water from 
the aquifer; permits for municipal wastewater discharge; agricultural 
irrigation; use of pesticides and herbicides; Environmental Protection 
Agency National Pollutant Discharge Elimination System permits; section 
18 exemptions under the Federal Insecticide, Fungicide, and Rodenticide 
Act; and Corps of Engineers permits for stream crossings.
    The Act and implementing regulations found at 50 CFR 17.21 set 
forth a series of general prohibitions and exceptions that apply to all 
endangered wildlife. These prohibitions, in part, make it illegal for 
any person subject to the jurisdiction of the United States to take 
(includes harass, harm, pursue, hunt, shoot, wound, kill, trap, or 
collect; or to attempt any of these), import or export, ship in 
interstate commerce in the course of a commercial activity, or sell or 
offer for sale in interstate or foreign commerce any listed species. It 
is also illegal to possess, sell, deliver, carry, transport, or ship 
any wildlife that has been taken illegally. Certain exceptions apply to 
agents of the Service and State conservation agencies.
    Permits may be issued to carry out otherwise prohibited activities 
involving endangered wildlife species under certain circumstances. 
Regulations governing permits are at 50 CFR 17.22 and 17.23. Such 
permits are available for scientific purposes, to enhance the 
propagation or survival of the species, and/or for incidental take in 
connection with otherwise lawful activities. It is anticipated that few 
trade permits would ever be sought or issued because these species are 
not known to be in trade.
    It is the policy of the Service (59 FR 34272) to identify to the 
maximum extent practicable at the time a species is listed or proposed 
to be listed those activities that would or would not constitute a 
violation of section 9 of the Act. The intent of this policy is to 
increase public awareness of the effect of a listing on proposed and 
ongoing activities within a species' range. The Service emphasizes that 
this action is a proposed listing, and that the guidelines presented 
herein are for use in the event that the listing becomes final. Should 
the listing become final, the discussion and outline presented here 
should assist landowners and managers in avoiding violation of section 
9 of the Act. The Service believes that, based on the best available 
information, activities that could potentially harm the Comal 
invertebrates and result in ``take'' include, but are not limited to--
    (1) Collecting or handling of the species;
    (2) Activities that may result in destruction or alteration of the 
species' habitat (including, but not limited to withdrawal of water 
from the aquifer to the point at which habitat becomes unsuitable for 
the species, alteration of the physical habitat within the spring runs, 
or physical alteration of the spring orifices or of the subsurface 
pathways providing water to the springs);
    (3) Discharge or dumping of chemicals, silt, pollutants, household 
or industrial waste, or other material into the springs or into areas 
that provide access to the aquifer and where such discharge or dumping 
could affect water quality; or
    (4) Herbicide, pesticide, or fertilizer application in or near 
springs containing the species or areas that drain into the aquifer. 
Careful use of pesticides in the vicinity of the springs may be 
necessary in some instances.
    The Service believes that a wide variety of activities would not 
harm these species if undertaken in the vicinity of their habitats and 
thus would not constitute taking. In general, any activity in the 
contributing, recharge, or artesian zones of the Edwards aquifer that 
would not have potential for cumulative or acute/catastrophic decrease 
in water quality within the aquifer and would not involve use of water 
from the aquifer should not harm these species. Inquiries concerning 
the possible effects of specific activities should be directed to the 
Service's Texas State Office (see ADDRESSES, above).

Public Comments Solicited

    The Service intends that any final action resulting from this 
proposal will be as accurate and as effective as possible. Therefore, 
comments or suggestions from the public, other concerned governmental 
agencies, the scientific community, industry, or any other interested 
party concerning this proposed rule are hereby solicited. Comments are 
particularly sought concerning:
    (1) Biological, commercial trade, or relevant data concerning any 
threat (or lack thereof) to Peck's cave amphipod, the Comal Springs 
riffle beetle, and Comal Springs dryopid beetle;
    (2) The location of any additional populations of these species and 
the reasons why any habitat should or should not be determined to be 
critical habitat as provided by Section 4 of the Act;
    (3) Additional information concerning the ranges, distributions, 
and population sizes of these species;
    (4) Current or planned activities in the subject area and their 
possible impacts on these species; and
    Final promulgation of the regulations on these species will take 
into consideration the comments and any additional information received 
by the Service, and such communications may lead to a final regulation 
that differs from this proposal.
    The Endangered Species Act provides for a public hearing on this 
proposal, if requested. Requests must be received within 45 days of the 
date of publication of the proposal. Such requests must be made in 
writing and addressed to State Administrator, U.S. Fish and Wildlife 
Service (see ADDRESSES section).

National Environmental Policy Act

    The Fish and Wildlife Service has determined that an Environmental 
Assessment, as defined under the authority of the National 
Environmental Policy Act of 1969, need not be prepared in connection 
with regulations adopted pursuant to Section 4(a) of the Endangered 
Species Act of 1973, as amended. A notice outlining the Service's 
reasons for this determination was published in the Federal Register on 
October 25, 1983 (48 FR 49244).

References Cited

Aller, L., T. Bennett, J.H. Lehr, R.J. Petty, and G. Hackett. 1987. 
DRASTIC: a standardized system for evaluating groundwater pollution 
potential using hydrogeologic settings. U.S. Environmental 
Protection Agency. EPA/600/2-87/035. 622 pp.
Barr, C.B. 1993. Survey for two Edwards Aquifer invertebrates: Comal 
Springs dryopid beetle Stygoparnus comalensis Barr and Spangler 
(Coleoptera: Dryopidae) and Peck's cave amphipod Stygobromus pecki 
Holsinger (Amphipoda: Crangonyctidae). Prepared for U.S. Fish and 
Wildlife Service. 70 pp.
Barr, C.B., and P.J. Spangler. 1992. A new genus and species of 
stygobiontic dryopid beetle, Stygoparnus comalensis (Coleoptera: 
Dryopidae), from Comal Springs, Texas. Proc. Biol. Soc. Wash. 
105(1):40-54.
Bosse, L.S., D.W. Tuff, and H.P. Brown. 1988. A new species of 
Heterelmis from Texas (Coleoptera: Elmidae). Southwestern Naturalist 
33(2):199-203.
Brown, H.P., and C.B. Barr. 1988. First report of stygobiontic 
(subterranean) riffle beetles in North America. Program abstract for 
April 22, 1988, meeting of Southwestern Association of Naturalists. 
5 pp.
Brune, G. 1981. Springs of Texas, Volume 1. Branch-Smith Inc., Ft. 
Worth, Texas.
Chapman, R.F., 1982. The Insects: Structure and Function. Harvard 
University Press, Cambridge, MA. 919 pp.
Edwards Underground Water District. 1989. Compilation of hydrologic 
data for the [[Page 29543]] Edwards Aquifer, San Antonio area, 
Texas, 1988, with 1934-88 summary: Bulletin 48, 157 pp.
Edwards Underground Water District. 1992a. Report of the technical 
data review panel on the water resources of the south central Texas 
region. 307 pp.
Edwards Underground Water District. 1992b. Investigation of the 
fresh/saline water interface in the Edwards Aquifer in New Braunfels 
and San Marcos, Texas. Report 92-02. 18 pp.
Edwards Underground Water District. 1993. Urban Development on the 
Edwards Aquifer Recharge Zone. Report 93-09. 40 pp.
Guadalupe-Blanco River Authority. 1988. The Edwards Aquifer: 
Underground River of Texas. Guadalupe-Blanco River Authority, 
Seguin, Texas. 63 pp.
Holsinger, J.R. 1967. Systematics, speciation, and distribution of 
the subterranean amphipod genus Stygonectes (Gammaridae). Bull. U.S. 
Nat. Mus. 259:1-176.
Longley, G. 1991. Status and trends of the Edwards (Balcones Fault 
Zone) Aquifer in the San Antonio Region. pp. 4-18 In: Proceedings of 
South Texas Irrigation Conference. Guy Fipps, ed. 146 pp.
McKinney, D.C., and D.W. Watkins, Jr. 1993. Management of the 
Edwards Aquifer: A critical assessment. Technical Report CRWR 244. 
Center for Research in Water Resources, Bureau of Engineering 
Research. University of Texas at Austin. 94 pp.
Technical Advisory Panel. 1990. Technical factors in Edwards Aquifer 
use and management. Prepared for Special Committee on the Edwards 
Aquifer. 57 pp.
Texas Water Commission. 1989. Ground-water quality of Texas--an 
overview of natural and man-affected conditions. Austin, Texas. 197 
pp. and 3 plates.
Wanakule, N. 1990. Stochastic drought analysis of the Edwards 
Aquifer. Edwards Aquifer Research and Data Center No. R1-90, San 
Marcos, Texas. 32 pp.

    Authors: The primary authors of this rule are Ruth Stanford and 
Alisa Shull (see ADDRESSES section) and George Drewry, Division of 
Endangered Species, U.S. Fish and Wildlife Service, 452 ARLSQ, 
Washington DC 20240.

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Proposed Regulations Promulgation

PART 17--[AMENDED]

    Accordingly, the Service hereby proposes to amend part 17, 
subchapter B of chapter I, title 50 of the Code of Federal Regulations, 
as set forth below:
    1. The authority citation for Part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C. 
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.

    2. Section 17.11(h) is amended by adding the following, in 
alphabetical order under Crustaceans and Insects, respectively, to the 
List of Endangered and Threatened Wildlife to read as follows:


Sec. 17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                      Species                                                    Vertebrate population                                                  
----------------------------------------------------      Historic range          where endangered or      Status    When listed    Critical    Special 
       Common name              Scientific name                                       threatened                                    habitat      rules  
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                        
                   *                  *                  *                  *                  *                  *                  *                  
CRUSTACEANS:                                                                                                                                            
                                                                                                                                                        
                   *                  *                  *                  *                  *                  *                  *                  
    Amphipod, Peck's cave  Stygobromus               U.S.A. (TX).............  NA......................  E           ...........           NA         NA
                            (=Stygonectes) pecki.                                                                                                       
                                                                                                                                                        
                   *                  *                  *                  *                  *                  *                  *                  
INSECTS:                                                                                                                                                
    Beetle, Comal Springs  Stygoparnus comalensis..  U.S.A. (TX).............  NA......................  E           ...........           NA         NA
     dryopid.                                                                                                                                           
                                                                                                                                                        
                   *                  *                  *                  *                  *                  *                  *                  
    Beetle, Comal Springs  Heterelmis comalensis...  U.S.A. (TX).............  NA......................  E           ...........           NA         NA
     riffle.                                                                                                                                            
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Dated: May 23, 1995.
Mollie H. Beattie,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 95-13457 Filed 6-1-95; 8:45 am]
BILLING CODE 4310-55-P