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Water Quality

Here we use the term Water Quality in a broad sense to include the physical, chemical, and biological quality of the Cahaba River. The Cahaba is, in some respects, one of the most studied streams in Alabama. Still, demonstrating long-term declines in water quality is challenging because stream systems are very dynamic and because it is rare to have long-term monitoring information from any one location to assess over time. The decline in the variety and abundance of aquatic species we see in the Cahaba River is one of the clearest indicators of our failure to adequately protect the health of this remarkable river.

Most of the Cahaba River Society’s activities are at least indirectly related to improving water quality in the Cahaba River. Those programs most directly related to water quality improvement are the following:

Reducing Pollution: TMDL Science

From 1988 to 1998, the Society urged ADEM to re-evaluate what we viewed as excessive loading of treated wastewater to the Cahaba River. We also made those same scientifically-based arguments to EPA because they have some oversight responsibilities for ADEM’s administration of the Clean Water Act. We presented EPA with information from the U.S. Fish & Wildlife Service, local scientists, and the Geological Survey of Alabama that we believed demonstrated that significant water quality problems were occurring in the Cahaba River.

On November 12, 1999, EPA directed ADEM to include 106 miles of the Cahaba River on the state’s official list of streams that do not meet water quality standards of the Clean Water Act, the 303(d) list. This was based on information from ADEM, the Alabama Natural Heritage Program, and the U.S. Fish & Wildlife Service. Our efforts to organize that information and keep it in front of decision-makers at EPA contributed to EPA’s decision to require ADEM to include the affected Cahaba River segments on that list of impaired waters.

The two most significant problems facing the Cahaba River are excessive amounts of siltation and nutrients. ADEM has acknowledged that 106 miles of the Cahaba River are impaired due to excessive amounts of these pollutants. Under the Clean Water Act, when streams are listed as impaired, ADEM is required to develop a plan to achieve compliance with state water quality standards. Those are called Total Maximum Daily Load, or TMDL, plans.

TMDL’s are essentially a “pollution budget” for a water body, identifying how much of a particular pollutant that the water body can assimilate and remain healthy, and determining how to reduce the that pollutant to that level. TMDL plans should evaluate at least three things: How much pollutant loading the river can assimilate; how much pollutant the stream is currently receiving from permitted and unpermitted sources; and who is responsible for diminishing excessive pollution loading to achieve water quality standards.

In the intervening 10 years, EPA has developed a Nutrient Target (an acceptable level of phosphorus for the Cahaba River) and ADEM has determined the concentration of phosphorus for the discharge from wastewater treatment plants that should allow the stream to meet the nutrient target. In September of 2006 ADEM finalized the “Cahaba Nutrient TMDL”.

However, ADEM has not yet re-issued NPDES permits that require that those limits be achieved despite the fact that most of the NPDES permits for wastewater treatment plants in the Cahaba River basin have expired. ADEM tells us they are negotiating with the various municipalities, including Jefferson County, to determine when the municipalities can adequately upgrade their treatment plants and thereby be able to achieve the discharge limitations that should be protective of the river. In the mean time, ADEM “administratively extends” the old permits, thus allowing the discharges that are known to be excessive to continue.

What’s the Problem with TMDLs ?

There have been a large number of stream segments in the Cahaba River basin (and elsewhere around the state and nation) where the cumulative effects of “legally allowable” pollutant discharge by individual permittees have resulted in stream degradation. (Current water quality standards do not adequately consider the cumulative effects of multiple pollution sources or the potential interactions of one pollutant with another pollutant.)

TMDL studies can help if there are sources of pollution that can be managed and if ADEM will impose the limits on dischargers called for by the study. In the Cahaba basin, there is hope that nutrients can be reduced because the largest sources of excessive nutrients are wastewater treatment plants, which can reduce their nutrient loading. At the time of this writing, however, ADEM has not issued NPDES permits with stricter nutrient limits. Instead, ADEM has persisted in “administratively extending” old permits with less stringent limits.

It has taken about 16 years to get segments of the Cahaba River appropriately listed as impaired and about 3 years to complete the TMDL study. We are still working to see more stringent standards applied to waste treatment plants and we are still waiting for those facilities to install the appropriate technology to achieve basic water quality standards.

In October of 2003, ADEM produced a DRAFT TMDL for Siltation that would apply to 106 miles of the Cahaba River mainstem. We’ve been told by ADEM that the Sediment TMDL will be finalized soon.

What’s the Problem with Siltation?

image2When particles of soil, silt, and earth from poorly managed construction sites and other sources enter a stream, they eventually settle to the stream bottom. This process of silt dropping out is known as “siltation”. It can cause a variety of problems in streams. For example, spawning habitats and living space is simply smothered by excessive siltation. Without appropriate habitat, aquatic wildlife moves elsewhere or fails to reproduce.

The result is few individuals and fewer species of our native fishes, mussels, and snails are able to survive. Suspended sediment in the water column abrades gill surfaces of fishes and macroinvertebrates. Also, sediment can serve as an effective “conveyor belt”, carrying pollutants (pesticides, heavy metals, wood preservatives, etc.) into our streams.

In 2006, ADEM and EPA finalized a Nutrient TMDL for 106 miles of the mainstem. That TMDL calls for significant reductions in discharges of phosphorus from wastewater treatment plants that discharge to the Cahaba River.

What’s the Problem with Nutrients ?

Excessive amounts of phosphorus and nitrogen, the typical ingredients in fertilizer, cause enormous amounts of algae to grow in our streams. Like too much sediment, excessive algae growth will smother spawning habitat and living space. In addition, algae can deplete essential dissolved oxygen during the nighttime hours when no photosynthesis is occurring. In summer, when water levels are low and hot temperatures also reduce oxygen levels in the river algae from nutrients can cause fish kills.


In the Cahaba River, these nutrients are predominantly from wastewater treatment plants. As the ability of these facilities to remove nutrients from their effluent improves, other factors may become more significant, but for now, the greatest reductions in nutrient loading will come from municipal wastewater treatment facilities.

What is an NPDES Permit?

In most states, administrative authority of the Clean Water Act is delegated to the state by the Regional EPA authority. Thus, violations of state regulations are a matter for state enforcement rather than federal enforcement. To control how much pollution is released by a facility, ADEM issues a “National Pollutant Discharge Elimination System” permit (They use the word “Elimination” because the Clean Water Act states the goal of the Act is to eliminate the discharge of pollutants by 1985”. Fortunately or unfortunately, depending on your perspective, the United States has given up on totally eliminating the discharge of pollutants to our streams.).

Improving Stormwater Quality and Quantity

When the Clean Water Act was first put in place, the greatest pollution problems were associated with “point sources”. These are discharges from a discrete location, usually pipe, from an industrial facility or municipal waste treatment facility. The CWA and ADEM have been notably successful (with notable exceptions) in reducing the discharge of pollutants from point sources. ADEM disserves credit for achieving those tremendous reductions in pollution discharge.

As those severe pollution problems began to be cleared up, environmental regulators began to recognize that “non-point source pollution” (pollution from diffuse sources, like stormwater runoff from agricultural or urban areas, or for example, oil and grease dripping from our automobiles onto roadways that are then washed into streams by rain events) was also contributing significant amounts of pollution to our streams. Indeed, regulators recognized that without an effort to control those non-point pollution sources, we would continue to degrade the quality, health, and usefulness of our streams.

So, another area of our organizational focus is on improving stormwater quality and quantity. Non-point pollution control is in many ways, more challenging than controlling point-source pollution. Regulations and permitting are not as effective an approach for non-point pollution control. Education and improving public awareness are essential components in reducing non-point source pollution. Each and every one of us contribute pollution to our local streams through stormwater runoff. However, relatively small changes in our behavior, if adopted by the majority of our population, can dramatically reduce this type of pollution. It is one goal of our organization to promote those individual choices that are most effective in reducing stormwater pollution.

What’s the Problem with Stormwater ?


Since water is such an effective solvent, a tremendous variety of potentially harmful chemicals will either dissolve into or be physically carried in an undissolved state by water down hill to stormwater drains and eventually to streams that are tributaries to the Cahaba River.

Water that enters storm drains will not receive any type of treatment to remove pollutants. Therefore, any chemicals that are outdoors and exposed to the rain are very likely to end up being washed into a stream.

Pesticides, wood preservatives, fertilizers, detergents, and especially petroleum-based products are all toxic to aquatic wildlife. In sufficient concentrations, any of these degrade in-stream water quality and can cause loss of aquatic wildlife (fish kills, for example).

CRS has supported the regional stormwater management efforts in the Cahaba River basin like Jefferson County’s Storm Water Management Authority (SWMA) and Shelby County’s stormwater program. Our Executive Director, Beth Stewart was co-chair of a large group of county-wide stakeholders that proposed the structure and role of Jefferson County’s SWMA. We believe an effective program of education and enforcement is essential for reducing storm water pollution in construction runoff and keeping the chemicals we use in our daily lives from making their way into the Cahaba River.

Our staff responds to calls we receive from citizens with concerns about potential pollution problems. We investigate those concerns and then engage the appropriate responsible enforcement agency.

Acid Mine Drainage Projects

For the past three years (2005-2007), CRS has received some tremendous help from volunteers with the Office of Surface Mining – VISTA program. Katie Pezzillo and Elizabeth Salter have made great progress in surveying, identifying, and prioritizing potentially harmful acid mine runoff sites. As a result, with the wonderful cooperation of Steve Miller, Refuge Manager for the Cahaba River National Wildlife Refuge, Jeff Gillespie with the federal Office of Surface Mining, and Larry Barwick with Alabama’s Office of Surface Mining, the Office of Surface Mining has reclassified the strip mined area and high wall on the Cahaba River National Wildlife Refuge to a higher priority for reclamation. We are hopeful that reclamation work on this area will begin soon.

What’s the Problem with Acid Mine Drainage ?

When iron sulfide, a natural component in the earth, is exposed to oxygen during a strip mining operation, a series of chemical processes yield sulfuric acid and precipitates of iron (also known as “yellowboy”). These acids can be generated in great quantities. The resulting low pH causes metals in the earth to be solubilized, allowing much greater than normal quantities of these metals to be mobilized in the environment.


The effect on biological systems can be dramatic. The precipitating “yellowboy” can smother streambed habitat and the acidity and abundant heavy metals may attack a variety of physiological processes essential for life. There can be some negative impacts on native wildlife even if little pH change can be documented.

Improving Water Quality Standards at the Local and State levels

The Cahaba River Society is working on a number of fronts to improve water quality standards at the local and state levels. While these efforts are perhaps, for most people, less interesting than our other activities, they are fundamentally important ways to improve the awareness and policies adopted and enforced by our government. We will discuss the following general areas in greater detail below:

Work to improve water quality standards, especially at the state and local levels

State and local governments are appropriately required to commit the standards and regulations they administer to the written page to allow the regulated community and the general public to understand more clearly what is expected in our day-to-day activities. There are occasional opportunities for the public to express opinions about existing regulations and standards. However, you must actively seek out those opportunities for public comment; as a result, the opportunity to express the need for high standards and the seriousness of achieving adequate environmental compliance rarely comes to the attention of most citizens. We do our best to take great advantage of those rare opportunities so our elected officials and appointed regulators fully appreciate our member’s concerns and expectations regarding full consideration of environmental protection and compliance.

For example, we comment on NPDES permits when those are put out for public comment. This entails a thorough assessment of the many assumptions made by the permit writer. Very often, the amount of pollution discharge allowed is calculated using a mathematical model or some other protocol. It is critical to critique those models and protocols because there are so very many aspects where the modeler or permit writer may have been misinformed or where incorrect assumptions may have occurred.

Encourage local county and city governments to adopt river sensitive ordinances

Local government is charged with the role of protecting the health, welfare, and the general conditions of that community. The community collectively decides how stringent local standards, including environmental standards, shall be. This is often accomplished through ordinances. The Cahaba River Society attempts to educate local decision makers about the significance and importance of our river to those communities and how their decisions impact the health of the river and their citizens.

Seek enforcement of existing environmental and community planning regulations

Environmental enforcement responsibilities are distributed among a variety of local, state, and federal agencies. Knowing which agency is responsible for what regulation is confusing for everyone. It takes more time to sort through such questions than most citizens can afford to yield. We are committed to understanding which agency is at least theoretically responsible for taking responsibility for these matters. We are committed to pressing the responsible agency for appropriate action, even if we are not always successful in achieving that goal. Unfortunately, we do encounter situations where appropriate policies are not adopted, nor are appropriate enforcement steps taken. But, we do keep trying to achieve that goal for the sake of our river, our members, and our community.

Promoted the ADEM Reform Coalition


Encourage ALDOT to diminish the direct and indirect impacts of highway development (especially the Northern Beltline)



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