Cabezon Creek WSA, NM
Railroad Valley Oil Well, Battle Mountain NV Antelope in New Mexico Arrow-leaf balsam root in Montana Wind Turbine Fire Management Officer in Eugene, OR
BLM>More BLM Programs>Soil, Water and Air Program>Water Resources>Water Quality
Print Page
Water Resources

Water Quality

The Bureau of Land Management (BLM) has responsibilities to protect water quality based on mandates of the Federal Land Policy and Management Act, the Clean Water Act, and other laws and regulations. The BLM cooperates with the EPA, States, and Tribes who establish water quality standards, conduct assessments, and identify those water bodies that do not meet standards. The BLM analyzes proposed uses of the public lands, and develops mitigation measures to prevent adverse impacts to water quality that could result from those uses.

Water Quality Standards (WQS)

The EPA is the federal agency with the primary responsibility to meet the requirements of the Clean Water Act (CWA). The EPA has delegated the responsibility to develop comprehensive WQS to the states. The WQS must be specific to particular bodies of water of the state and consist of the following three parts:

Designated beneficial uses of a waterway (e.g., public drinking water supplies, propagation of fish and wildlife, recreation, industrial use, and agriculture);

Specific water quality criteria designed to protect those uses (expressed in numerical terms and/or through narrative statements); and

A prohibition against degradation of the existing uses of the water.

Section 303(d) of the CWA outlines a water protection program that is intended to clean up waters that remain polluted even after the application of technology-based limitations. A state’s 303(d) list identifies water bodies where WQS are violated by one or more pollutants. The program requires the states to do the following:

Identify waters that are and will remain in violation of state WQS after the application of technology-based controls;

Prioritize these waters, taking into account the severity of their pollution; and

Develop Total Maximum Daily Loads (TMDLs) that will allow polluted water bodies to meet WQS, accounting for seasonal variations and a margin of safety.

The BLM and Federal Land Managers have the responsibility under the CWA to comply with the Act and applicable WQS in the same manner and to the same degree as any other entity. The BLM’s water quality management responsibilities do not involve enforcement to any significant extent.

The BLM’s land health assessments require the BLM to determine whether applicable water quality standards are being met, or whether significant progress is being made toward achieving compliance with water quality standards. Water quality standards (as well as water use rights to water quantity) is a strongly regulated area, with federal, state, and sometimes local and tribal requirements as well. Non-point sources also influence water quality; therefore, BLM also must consider non-point sources in evaluating water quality. Nonpoint sources of pollution such as agriculture, construction, forestry, and mining are responsible for much of the nation’s remaining water quality impairment. On federal land, the most important nonpoint sources of pollution are timber harvesting, livestock grazing, road building, and mining.

Administration of State Water Quality Laws

New Mexico
Utah Department of Environmental Quality (DEQ):

Inventory/Baseline Data

Where water quality and water uses are an issue, the BLM Water Resources Specialist establishes what is known about water quality and who has collected what data, evaluates existing data, and decides whether an inventory effort is needed. Depending on the project or stage of land management planning, there are sometimes several options for obtaining new inventory data. One approach BLM can use to save money is to look for an organization that also has a need for obtaining data, and developing a single plan for water quality inventory that meets objectives of the BLM and the partnering entity.


Monitoring may be conducted for a variety of reasons. Water quality monitoring can be used to:

  • Analyze trends
  • Determine fate and transport of pollutants
  • Define critical areas
  • Assess compliance
  • Measure effectiveness of conservation practices
  • Evaluate program effectiveness
  • Make waste load allocations
  • Validate and calibrate models
  • Conduct outreach
  • Define water quality problem(s)

Measurement of water quality constituents, such as pH or dissolved oxygen is used to identify problem areas, trends in water quality, and for National Pollutant Discharge Elimination System (NPDES) compliance and monitoring. Monitoring usually implies more frequent water sampling than just one time, perhaps quarterly or monthly, or even weekly. Many resources are available to the BLM in water quality monitoring, including assistance from agencies such as the U.S. Geological Survey, the state, and local soil and water conservation districts. Monitoring goals are usually determined by regulatory requirements, identified water quality issues, and water use/water quality conflicts.

To determine whether water quality standards are being met, states monitor their waters by collecting water samples or other indicators such as sediment, fish, or macro-invertebrates. States select which water bodies to monitor, determine the conditions for which it will sample and test, and determine how often to sample. In addition to their own data, states can use data from other sources.


Water bodies not meeting water quality standards need to be remediated. The BLM is required to comply with state and local water quality standards. If standards are not being met, the state works with BLM and other relevant entities to determine the causes for non-compliance, and whether the actions of BLM or those of a public lands user are the source of the problem. The cause of the water quality problem may be above a BLM boundary on a different land ownership. Typically better results are obtained by taking an inclusive basin-wide approach to water pollution to understand all sources of pollutant loading and to craft more cost-effective solutions.

Best Management Practices (BMPs)

BLM encourages and often requires the use of BMPs for livestock grazing, mining, oil and gas development and production, and other activities conducted on the public lands. BMPs prevent or reduce the impacts, such as surface disturbances, of authorized uses that may impact water resources. Measures can include, but are not limited to structural and non-structural controls, and operations and maintenance procedures. Frequently, several BMPs are used together to address a problem. BMPs should not be viewed in isolation but rather as a management strategy system. The development and implementation of BMPs should be seen as an iterative feedback loop system which is informed by the results of water quality monitoring. A commitment is needed to periodically monitor the BMP and its effectiveness using water quality monitoring and other data as indicators, and then adjusting the BMP(s) as needed. For more information see BLM’s BMP web page for oil and gas production and fact sheet for fluid minerals.

Specific Key Parameters

There are many parameters that can be measured and analyzed to evaluate water quality. The following are some of the key parameters that BLM and/or the states monitor to ensure that water sources on public lands meet the relevant state water quality standards:

Total Suspended Solids/Sediments Water moving off wildland watersheds picks up debris as it moves from a slope, into a rill of more concentrated flow, and eventually into a network of increasingly larger channels. The velocity of water movement, volume of water movement, and channel characteristics, combined with the soil surface and plant cover are all important factors in how much suspended solids are in the water. Suspended solids are comprised of organic particulates (generally woody and vegetative in origin) and inorganic particulates (sediments). The usual procedure to measure total suspended solids/sediment is to filter a water sample using a 0.45 micron membrane type filter which separates the suspended material from the water. Sediments may be subdivided into size classes of particulate diameter (e.g., clay, silt, and sand). Sediment is often the single most important parameter in surface water runoff from public lands, and some chemical pollutants, such as salts, nutrients, and mercury, may be transported to water bodies with sediment.

Metal Contamination and pH The observed pH of natural water is the indication of the level of hydrogen ion activity in water. Note that acidity and pH are not the same thing. The pH of pure water at 25°C is 7.0. Most water in streams varies in pH from 6.5-8.5, and most groundwater varies in pH from 6.0-8.5. pH can be measured in the field with a meter. The degree to which various metals (e.g., iron, lead, and zinc) will be soluble in a water sample is heavily dependent on the pH of the water.

Bacterial and Viral Pathogens Water that is free of chemical contaminants still might not be safe to drink because it may contain bacteria or other pathogens. Drinking water supplies provided at BLM facilities are routinely tested for the presence of total coliform bacteria. Coliforms themselves may not pose a health risk, but may indicate a problem with a drinking water system. If a sample tests positive for coliforms, another test is immediately performed for the presence of fecal coliforms or E. coli bacteria, which are harmful to humans. These bacteria are present in the environment, but should not be found in drinking water, so whenever they are detected, the system will be closed until the source of contamination is eliminated.

Thermal Pollution/Temperature High water temperatures can lead to a reduction in available dissolved oxygen in water, and thus impact aquatic biota that need that oxygen. Elevated water temperatures in settings managed by the BLM are generally associated with a lack of shade-cover from brush or overhanging tree branches in the riparian zone near the water. Activities that reduce plant cover and cause soil disturbance can also make stream channels wider and shallower, making them more susceptible to heating from the sun.

Total Dissolved Solids (TDS)/Salinity Salinity is often termed total dissolved solids (TDS) because it is the concentration of TDS in water, hence the terms are interchangeable. Salts are among the most common chemical compounds found on the Earth. They leave a residue when evaporated, and salts are frequently a pollutant of water bodies. Salinity is defined as the total quantity of inorganic soluble constituents (mineral salts) that are found in a water sample. Inorganic matter that is dissolved in the water sample is in its ionic form, such as sulfate anions and calcium cations. The presence of these charged ions makes the water a conductor of electricity, and the greater the concentration of these dissolved solids, the greater the conductance properties of the solution. A complete laboratory analysis of all dissolved constituents is the most thorough determination of TDS. A measure of specific conductance of the water sample (by field meter measurement) is often used as a predictor of TDS.

Dissolved Oxygen (DO) The equilibrium concentration of dissolved oxygen (DO) in water that is in contact with air is the dissolved oxygen concentration, usually expressed in milligrams per liter of water (mg/L). The DO concentration is mainly a function of the water temperature and atmospheric pressure. Most aquatic life requires oxygen in this form, and thus DO has become an important parameter of aquatic health. Oxygen enters groundwater aquifers through recharge of precipitation, and by movement of oxygen through overlying unsaturated strata above the water table. DO is a key parameter in BLM fishery and riparian improvement projects, and it can be measured by a field meter.

Inventory, Monitoring and Assessment
·Water Quality
·Water Quantity
Resource Use and Management
Partners and Coordination
Salinity Program
Technical Guidance and Policy
Laws and Regulations