This report is not intended to be an exhaustive examination of the data, but rather a brief review of the available information.  More detailed data sets will be developed in the course of the 2001 intensive water quality survey of these watersheds.

The Viveash fire as seen from Las Vegas, New Mexico, on the afternoon of May 30, 2000.  The fire consumed 20,000 acres on that day.	Photo courtesy of Sarah A. Frazier

Due to limited resources, chemical analyses were restricted to reaches downstream of burned areas.  The Pecos River was sampled at a newly established station just upstream from Interstate 25, below the confluence with Cow Creek, which drains the southern end of the area burned by the Viveash fire.  Streamside measurements were taken at an existing station on the Pecos River above State Highway 63 bridge near the north end of the Village of Pecos.  Because of municipal water supply, irrigation and primary contact concerns on the Gallinas River, samples were drawn at several locations situated to define contamination levels at relevant locations in that watershed.  No above-impact comparison stations were established on the Gallinas River because the Viveash fire entered the watershed in its uppermost reaches.

In addition to sampling conducted in watersheds draining the Viveash burn area, samples were taken at three locations receiving runoff from areas affected by the smaller, but no less intense, Manuelitas fire.  The Manuelitas fire samples were obtained from two stock ponds and a spring in arroyos receiving runoff from the east flank of the burned area.  Both ponds had accumulated heavy deposits of ash.  On the initial visit (July 21, 2000), the upslope pond showed no evidence of life: there was no sign of insects, fish or amphibians.  Swallows, which are obligate insectivores, were conspicuously absent from the area.  The lower pond, in contrast, appeared to support a normal fauna.  The spring was selected for sampling because a dog belonging to a local resident had been found dead in the spring shortly after the fire.

Several accounts of livestock deaths were received after the Manuelitas fire.  Of these, only one producer is known to have invested in autopsies. The attending veterinarian determined that the mortalities were due to pulmonary edema attendant to smoke inhalation. (Ben Nelson, DVM, pers. com.).  Cyanide toxicity was not indicated by the findings of the autopsies.
 

Figure 1 – Areal extent and burn intensity of the Viveash fire.	Map courtesy of the Viveash BAER Team.

Water Quality Standards
Applicable general standards for the protection of designated and attainable uses are set forth at 20.6.4.12 NMAC (10/12/2000).  Segment-specific standards and designated uses are listed at 20.6.4.116 NMAC for the Pecos River above I-25.  Designated uses for segment 2213 include irrigation, livestock watering, wildlife habitat, marginal coldwater fishery and secondary contact.  Segment specific standards and designated uses are listed at 20.6.4.117 NMAC for the Pecos River above State Highway 63.  Designated uses for segment 2214 include domestic water supply, fish culture, high quality cold water fishery, irrigation, livestock watering, wildlife habitat and secondary contact.  Segment specific standards and designated uses are listed at 20.6.4.211 NMAC for the Gallinas River at the USGS gage near Montezuma and the Gallinas River at the end of Forest Road 263.  Designated uses for segment 2212 include domestic water supply, high quality cold water fishery, irrigation, livestock watering, wildlife habitat, municipal and industrial water supply and secondary contact.  Segment specific standards and designated uses are listed at 20.6.4.307 NMAC for the (reportedly) perennial Ortiz spring and other drainages in the area.  Designated uses for segment 2305.3 include marginal coldwater fishery, warmwater fishery, secondary contact, irrigation, livestock watering and wildlife habitat.  The State of New Mexico does not apply water quality standards to irrigation conveyances (Gallinas River at end of Storrie diversion).  Numeric standards applicable to the attainable and designated uses assigned to the above segments are set forth at 20.6.4.900 NMAC.

Methods
Water quality sampling methods were in accordance with the Quality Assurance Project Plan for Water Quality Management Programs (NMED, 2000), except that some water chemistry analyses that would normally be performed on whole water were performed on filtered water due to the nature of the sample matrix.  Where turbidity exceeded 1,000 NTUs, values were estimated by dilution.

Water Quality Assessment
Measurements were taken of dissolved oxygen (DO), pH, specific conductance and turbidity at most stations on all sampling runs.  Stations downstream of burned areas were sampled for nutrients (nitrate (NO₃), total ammonia (NH₃), total Kjeldahl nitrogen (TKN), total phosphorus (TP) and total organic carbon (TOC)); twelve ionic constituents (including chemical oxygen demand (COD)), and 27 metals in both the total and dissolved fractions.  Water and sediment samples were collected for cyanide analyses at most stations.  One sediment sample was taken for metals analysis.

On the first sampling run to the Pecos River (June 21, 2000), the water was black and smelled distinctly of smoke.  During subsequent sampling efforts water color had changed to dark brown and the odor of smoke was not as evident.   With the exception of the sampling effort on August 7, turbidity, TSS, TDS, TP, TKN, sulfate and COD were greatly elevated (see Table 4) in the Pecos River above I-25.  Phosphorus concentrations appear to be related to turbidity as a measure of suspended sediment loading (see Figure 2).  The standard for TDS (250 mg/L) was exceeded on June 21, June 28 and July 13.  The standard for sulfate (25 mg/L) was exceeded on June 21 and June 28.  While several metals were seen at elevated concentrations in the total fraction, notably mercury (see Table 2), only aluminum (dissolved chronic (87 µg/L)) and mercury (total chronic (12 ng/L)) exceeded standards in the Pecos River above I-25.  No other metals exceeded the chronic or acute standards at that station.  There were no metals exceedences of any kind on the Gallinas River (see Table 2).

The presence of mercury at 400 ng/L (ppt) in the Pecos River samples is problematic.  Mercury did not appear in ashy samples – mercury is a gas at 300ºC and would not be expected in samples containing high levels of ash.  Once the ash had been replaced by a suspended solids load consisting primarily of mineral sediment however, mercury appeared in highly elevated concentrations.  The source(s) of this mercury remains unexplained.  Two theories have been put forth to account for these elevated levels of mercury; both remain entirely speculative.  The first is that a substantial quantity of mercury was stored in one of the structures that was destroyed in the fire.  The second is that mercury was drawn towards the soil surface by the heat of the fire, condensed there as the soil cooled and later washed out of the burned area as erosion cut deeper into the soil surface.  Plans to try to isolate the source of this contaminant are being incorporated into the 2001 upper Pecos water quality study.

Cyanide was found in both water and sediment at the Pecos River above I-25 station (see Table 1), most of it probably bound to suspended sediments in water (see Figure 2).  While some cyanide is produced naturally in wildfires (Yokelson,R. J., et al., 1997), it is most likely that the cyanide found in the course of this survey was derived from fire retardant slurry.  The degree of toxicity attributable to the levels of CN- found in the Pecos River is difficult to determine.  Free cyanide is acutely toxic to salmonids at concentrations ranging from 30 µg/L (ppb) to 160 µg/L, depending on species.  Other species of freshwater fish are somewhat more tolerant (Moore, 1990).  The above values were developed using free CN-; the cyanide used in fire retardants is strongly bound to the sodium/iron complex and is therefore minimally biologically available.  Moreover, bioavailability is further reduced by adsorption to fine particulates (see Figure 2).  Concentrations seen in water were potentially high enough to elicit toxic reactions in aquatic life, but actual levels of free CN- and HCN are not known.  Observed levels were not high enough in water or sediment to produce toxicity in terrestrial organisms.  It is unlikely that any aquatic life could have survived the exceedingly high concentrations of ash long enough to have succumbed to cyanide toxicity.

In an effort to provide comparison data to the Cerro Grande fire, samples were collected for radionuclides on two occasions (see Table 3).  The initial sample (July 20, 2000) was a composite of Pecos and Gallinas river water.  The second sample (August 7, 2000) was Pecos River water.  No exceedences of radiological standards were found.  In general, levels of radionuclides found below the Viveash fire were lower than those associated with the Cerro Grande fire (Ralph Ford-Schmid, NMED DOE Oversight Bureau, pers. com.).

Only one sampling run was conducted on the Gallinas River.  On that day only one station (Gallinas R. at end of Forest Road  263) had ash deposits substantial enough to sample (see Figure 13).  With the exception of trace amounts of cyanide (3.0 µg/L), no water quality parameters were found to be elevated.  Despite finding the highest level of sediment cyanide (2,225 µg/kg) seen in the course of this investigation, the level of cyanide seen in whole water at the time of sampling was insufficient to kill aquatic organisms (see Table 1).  Trout were observed feeding during the sampling effort, and a cursory examination of the benthic macroinvertebrate community revealed a diverse and healthy community structure.  Water samples taken from the Gallinas River at the USGS gage near Montezuma and at the end of the Storrie diversion (CN- only) yielded no water quality standards exceedences.

In response to citizen complaints of water quality problems, two sampling runs were conducted below the 1,300 acre Manuelitas fire.  Three reports of discolored well water were received by the SWQB.  Only two complainants responded to NMED efforts to sample their wells (an effort mounted by staff of the Ground Water Bureau) and of those two, only the first had a functional well.  The second well had been filled by sediments carried by runoff from the Manuelitas fire and no longer produced water.  As stated above, the uppermost of a series of stock ponds appeared, on cursory inspection, to have been effectively sterilized.  Bank-side ash deposits and aqueous cyanide levels indicate that conditions prior to the initial sampling effort were potentially antagonistic to the maintenance of aquatic life.  The second pond in the series, while ringed with deposits of fine ash, showed no obvious signs of biologic impairment.  Mosquitoes, chironomids (midges) and assorted odonates (dragon flies) were abundant, as were swallows.  Frogs were heard calling.  This pond is approximately 300 linear feet below the first, and the distinct difference between the two remains unexplained.  It may be that the worst of the material from the initial flows washing off the burned area were trapped in the upper pond.

The owner of the property surrounding the two ponds reported that a dog belonging to one of his tenants had died unexpectedly and had been found in a spring rising in an arroyo draining the east face of the area affected by the Manuelitas fire.  This spring, once clear and cold, was found to be yellow and turbid following the passage of several flash floods down the arroyo.  A sample taken to test for cyanide showed no concentration of cyanide compounds at the time of sampling that could be considered dangerous to terrestrial vertebrates (see Table 1).

Conclusions
There are no tributaries involved in the Viveash fire between the Village of Pecos and Cow Creek.  Fire-related inputs to the Pecos River must then have come from the Cow Creek drainage.  Time and resource limitations allowed for only one visit to the Cow Creek watershed.  During that visit (August 7, 2000) Cow Creek was found to have incised approximately two feet into the alluvium of the canyon floor (Figures 4 – 10).  Extensive areas of recently exposed colluvial deposits were visible where the channel contacted the canyon wall.  Many ephemeral tributary drainages had already begun to rejuvenate (head cut).  No fish were observed during this visit.  A cursory examination of the macro-benthic community indicated that benthic invertebrates had been completely extirpated.  Deposits of ash and sediment were one to two meters deep in some low gradient areas below the burned area (see Figures 4, 6).  It has been reported by staff of the Forestry Division of the New Mexico Energy, Minerals and Natural Resources Department that by fall of 2000, Cow Creek had cut its channel another two to three feet deep (Charlie Wicklund, pers. com.).  Future runoff events and monsoon storms will almost certainly exacerbate this situation.  It is reasonable to assume that where the channel is eroding the canyon wall there will be significant episodes of mass wasting in the unsupported colluvium, accompanied by extensive rejuvenation of existing side drainages (See Figure 7).

The sediment moving through Cow Creek has the potential to produce significant impacts in the Pecos River, both in terms of water quality and hydrology.  Inputs of large quantities of bed load to the Pecos River channel will likely force channel adjustments as the river re-establishes equilibrium between its discharge, channel morphology and increased bed load.  While in a state of disequilibrium, the Pecos River channel will likely undergo a period of widening to accommodate flow through a shallower thalweg.  This widening will generate a reduction in sinuosity, (a measure of channel length relative to valley length).  A reduction in sinuosity will increase the slope of the channel relative to the slope of the valley floor, generating, to a greater or lesser degree, an episode of down cutting.  Local increases in gradient will move both up- and down stream, traveling until they meet a grade control such as bedrock or a diversion dam.

As the Pecos River below the Village of Pecos is already in a state of adjustment (disequilibrium), as indicated by many eroding, vertical banks (see Figure 11), the effects of additional sediment loading may be intensified.  Channel adjustments can result in significant losses of floodplain.  Increases in mobile sediments can also have serious impacts on the irrigation infrastructure, damaging diversion works and filling conveyances with mud.  It is conceivable that sediments mobilized during the period of re-adjustment will be of sufficient quantity to significantly reduce the storage capacity of Santa Rosa Reservoir.

The presence of relatively large quantities of mercury in Pecos River water poses an additional problem for Santa Rosa Reservoir and other impoundments downstream.  Every major reservoir on the Pecos River mainstem is currently under a fish consumption advisory for mercury.  The additional inputs of highly bio-accumulative mercury to these systems will most likely increase the levels of mercury in the tissues of fish in these reservoirs.  The Surface Water Quality Bureau is developing plans to monitor fish tissue mercury concentrations and other contaminants in these reservoirs during the 2001 sampling season.

While there may be increases of turbidity in the Gallinas River due to the Viveash fire’s encroachment into the upper watershed, it appears at this time that the damage was insufficient to cause the type of extreme impacts observed in the Cow Creek watershed (see Figures 5, 6, 7, 10 and 13).  Some ash was mobilized and traveled through Las Vegas, but the massive quantities of ash and sediment seen in Cow Creek were not evident.  Careful monitoring is called for, however.  Surveys conducted by the Viveash fire Burned Area Emergency Rehabilitation (BAER) team determined that, while nearly 800 acres of the Gallinas watershed were heavily damaged (Robbie et al., 2000), no drainages directly feeding the Gallinas River were seriously impacted.

There are no perennial tributaries impacted by the Manuelitas fire entering either Sapello or Manuelitas creeks.  It is nevertheless likely that ash and sediment will continue to be entrained in runoff from the burned area for some time.  The presence of stock ponds in most, if not all, of the arroyos draining the Manuelitas fire will serve to interdict much of the sediment before it can get to perennial waters.

Management of the aftermath of the Viveash and Manuelitas fires will fall primarily to staff of the Santa Fe National Forest.  The Tierra y Montes Soil and Water Conservation District, the New Mexico State Forestry Division, the Natural Resources Conservation Service, the City of Las Vegas, NM and numerous private landowners are also active in rehabilitation efforts.  The timeframe for a return to an equilibrium condition in the Cow Creek and Pecos River systems depends, to a considerable degree, on the extent and success of rehabilitation efforts.  The longer a state of disequilibrium exists, the greater the costs of damage to property and the environment will be.  It is critical that responsible agencies provide the resources and direction necessary to stabilize these burned watersheds.

Figure 4 – Upper Cow Creek, June 2000.	Photo courtesy of Charlie Wicklund, New Mexico Div. Of Forestry.

Figure 5 – Upper Cow Creek, June 2000.	Photo courtesy of Charlie Wicklund, New Mexico Div. Of Forestry.

Figure 6 – Upper Cow Creek, June 2000.	Photo courtesy of Charlie Wicklund, New Mexico Div. Of Forestry.

Figure 7 – Upper Cow Creek, June 2000.  Rejuvenation of a side drainage.	Photo courtesy of Charlie Wicklund, New Mexico Div. Of Forestry

Figure 8 – Cow Creek in flood below Santa Fe National Forest.	Photo courtesy of Charlie Wicklund, New Mexico Div. Of Forestry

Figure 9 – Upper Cow Creek, June 2000. Severe erosion of low gradient uplands.	Photo courtesy of Charlie Wicklund, New Mexico Div. Of Forestry

Figure 10 – Upper Cow Creek, June 2000	Photo courtesy of Charlie Wicklund, New Mexico Div. Of Forestry.

Figure 11– Pecos River, June 2000.  View down stream.  Note vertical bank in background..	Photo courtesy of  Dan Davis, NMED

Figure 12 – Pecos River, June 2000.  View upstream.  Note ash bar at left.	Photo courtesy of  Dan Davis, NMED

Figure 13 – Gallinas River, June 2000.  Note ash bar behind log. The banks are not eroding and there is no sign of flooding.	Photo courtesy of John Tingle, US Army Corps of Engineers

REFERENCES
 

Little, E. E. and Robin D. Calfee, US Geological Survey, Columbia Environmental Research
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Moore, J. W., 1990.  Inorganic Contaminants of Surface Water, Research and Monitoring
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Material Safety Data Sheet, 1/22/2001. http://gandalf.pp.orst.edu/msds/.
New Mexico Environment Department, 2000.  Quality Assurance Project Plan for Water Quality
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New Mexico Water Quality Control Commission, 2/23/2000. Standards for Interstate and
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Robbie, W. et al., 2000. Viveash Fire Burned Area Emergency Rehabilitation Report (BAER).
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Rosgen, D. and Hilton Lee Silvey, 1996.  Applied River Morphology, Wildland Hydrology,
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