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r � of heterotrophic bacteria which typically can lead to the inhibition of growth in the selective contaminant-degrading populations via competition for available inorganic nutrients. This factor alone can often dictate the feasibility and appropriateness of a biostimulatory or bioaugmentation approach. In addition to providing valuable information from a microbiological perspective, TOC analyses are also considered routine for NA or RBCA approaches by providing information pertaining to the sorption potential of chemical compounds and migratory activity (retardation), as well as providing indications of potential chemical desorption (concentration spikes), for example as a result of oxygen addition, as biological activity progresses. Iron II - Fe+z (Dissolved Iron, in situ only): The routine analysis of Iron (Il) provides initial information in detecting the development of precipitates (scaling) which could restrict intrinsic permeability and indications of the initial feasibility of transporting essential biological components (e.g., moisture, nutrients, oxygen, terminal electron acceptors, etc.). In addition, this analysis can commonly be utilized as a marker for indications of naturally-occurring intrinsic bioremediation (generally via anaerobic developments). In addition to conducting these baseline laboratory analyses, it is recommended that field personnel con- duct field analyses consisting of temperature, dissolved oxv_,gen, and redox potential measurements when collecting samples (please inquire with BioLogic for procedures and appropriate sampling techniques). EVALUATIONS OF THE EFFECTS OF PHYSICOCHEMICAL PARAMETERS Subsequent to obtaining baseline verification of microbial viability (via above testing), the following tests have primarily been designed for those desiring to pursue any form of indigenous applications. Whether the desired approach is to just let it passively sit in a stagnant pile or more active biostimulation, via nutrient, moisture, oxygen additions, tilling etc., the tests can cost-effectively address at least fundamental contribut- ing or limiting factors which may influence a selected approach, without incurring the time and expense of full-scale treatability studies. These simple evaluations can accommodate those choosing to minimize bioremedial/project expense, and/or who may automatically presume that ubiquitous bacteria will degrade a contaminant, by providing valuable information in advance as to whether and what degree microbial activity may/can occur, and in determining the appropriateness or operational requirements necessary for a selected approach in order to avoid project failure. In cases where baseline physicochemical and microbiological analyses produce less than desirable results for effecting site cleanup and/or indicate environmental incompatibility as demonstrated, for example, by low heterotrophic and selective population numbers, the issue of possible physicochemical limiting factors might be addressed. Low recoveries of microbial populations can be attributed to one or more specific growth-limiting conditions which tend to be site-specific and may include: environmental parameters such as nutrient concentrations, pH, temperature, oxygen, contaminant levels, and salinity. These tests, as described in the following sections, have been designed to evaluate the effects of individual parameters on the growth of indigenous heterotrophic and selective microbial populations in an effort to determine which, if any, of the factors may be limiting to microbial growth and biodegradation efficiencies. Each of the following evaluations is designed to be performed subsequent to obtaining baseline microbiological and physicochemical results, and will consist only of those evaluations of potential inhibiting factors as identi- fied from background analyses. Additionally, provided arrangements are made in advance, these tests can be performed on samples collected initially for background analyses. This can eliminate additional remo- bilization costs which would be incurred if further sampling were required in order to obtain the necessary supplemental data. 5