# Presentation: 376456

## Drinking Water Supply Watershed Area

**Notes:**
The Rocky Mountains are the source for most of Colorado’s water supply.  The watershed areas highlighted in light green and blue in this slide are typical of many watershed serving surface water treatment facilities all over the State.  The vast majority of the land area with these mountain watersheds is federally owned and subject to the land use management plans of either the United States Forest Service, the National Park Service, or Bureau of Land Management.  Consequently federal policy dictates how the local watersheds are managed and there are many competing uses for the land areas and the process for setting priorities is highly contentious and political.  

The watersheds are the source of drinking water  much of northeastern Colorado from the suburbs on the north side of Denver north almost to the Wyoming line and as far east as Fort Morgan.  The northern edge of Denver’s source water area can be seen on the far left side of the high mountain watershed.

## Slide 2

**Notes:**
This slide shows an arerial view of the upper Colorado River portion of the same watershed shown on the previous slide.  The large lake in the foreground is Lake Granby.  The water from Lake Granby is pumped east though Shadow Mountain Reservoir and Grand Lake, then flows by gravity tunnel to the east slope of the Rockies near the Town of Estes Park.

## Slide 3

**Notes:**
There are few sights in nature that are more pleasing to look at than a high mountain stream flowing though a healthy forest.

## Slide 4

**Notes:**
When improperly managed and when left completely to the vicious cycles of nature, forests can become unhealthy and subject to ravaging forest fires that often have devastating acute and chronic impacts on watersheds.  This photo was taken in the intense burn portion of the Bobcat Fire in the Big Thompson watershed.  This area burned in June of 2000 and still produces black water when runoff occurs in this portion of the watershed.

## Slide 5

**Notes:**
Black runoff from rain event in August of 2000.  

By the time the flow reaches this point it has been highly diluted by mixing with flow from major tributaries outside of the burned area.

## Continuous Flow -Through Water Treatment Processes

- Continuous Flow -Through Water Treatment Processes

- Raw Water Intake

- Chemical Preconditioning

- Chemical Addition

- Particle Settling

- Filtration

- Disinfection

- Distribution & Storage

- Chemical Addition

**Notes:**
Water treatment processes are linear, flow-through process, not batch reactors.  Consequently slugs of poor quality water tend to disrupt the stability of the water treatment processes.  Sudden changes in a wide array of parameters have the potential to cause violations of drinking water standards, reduce plant throughput and/or threaten public health.

For all practical purposes it is virtually impossible for any direct stream diversion water treatment plant to cope with the rapidly changing, process impacting variable associated with a runoff event from a burned area of the watershed.  The safest, most effective strategy for these plants is to close their intakes and allow as much as possible of the contaminated runoff to flow past their intake.  Unless the plant has alternate sources, or sufficient water storage, this option has the potential to interrupt water service to the customers.

## Slide 7

**Notes:**
This photo shows the linear process layout typical of most surface water treatment plants, although most have a more compact footprint than this old plant that originally located on the Cache La Poudre River in 1904.

## Loveland River Intake Sample 8/16/00

**Notes:**
The water sample in the bottle in the foreground contains runoff from the Bobcat fire.  The sample was collected at the plant intake during the crest of a post fire run-off event.

## < Rain event

**Notes:**
Bobcat Fire Date – June 2000

Sample collected in August of 2000

Normal background manganese level = approximately 30 ug/L

## Total Phosphorous

**Total Phosphorous**

- < Rain event

**mg/l**

**Notes:**
Bobcat Fire Date – June 2000

Sample collected in August of 2001

Normal background phosphorous level  is approximately  0.041 mg/L

## Mercury Levels -

- In-Stream Standard

-  Bobcat Fire Area Runoff

**Notes:**
  Stream standard for Hg = .10 ug/

 Sample collected in August of 2000, but not analyzed for Hg until May of 2001.  Despite exceeding the recommended maximum holding time some of the Hg levels exceeded stream standards by a factor of 3 or more.

## What Is The Most Effective Water Treatment Strategy(for Dealing With Post-Fire Runoff)

- ???

**Notes:**
In summary.........

## Slide 13

## What Can Be Done To Reduce Drinking Water Risks Related To Forest Fires?

- Forest fires are among the most serious threats to water quality ........and in many cases to the water supply itself.
- EPA’s Source Water Assessment Process (SWAP) must include an assessment of the risk to public health from drinking water contaminants derived from forested areas that have or someday will be impacted by forest fires.

**Notes:**
Recognize the fact that for many forested watersheds, forest fires are the most serious threat to water quality ........and in many cases to the total water supply. 

Recognize that in many instances, the EPA’s determination of acceptable levels of risk to public health from drinking water contaminants does not correlate well with forest management plans acceptable levels of probability for experiencing catastrophic forest fires........ and the inevitable, (virtually untreatable) slugs of contaminated runoff that continue occurring for several years after the fire.
Make sure that when EPA source water contaminant inventory and vulnerability assessments are performed on forested watersheds, the risk of catastrophic fire and the impact it could have on public water supplies is included in the assessment.

## What Can Be Done To Reduce Drinking Water Risks Related To Forest Fires?

- Conservation or Preservation
- BMPs
- Put “forest management” back into the hands of professional forest managers.

**Notes:**
Those responsible for public drinking water supplies should insist that in regions where the population is dependent upon a sustained yield of high-quality water from their publicly owned watersheds, forest management practices follow a conservation ethic “management for the long-term sustainability for benefit of mankind”, not preservation ethic “management that excludes mans uses and allows nature to run it’s course regardless of the consequences”.
Effective and appropriate BMPs must be applied to forest management.  Closely controlled prescribed burns are appropriate for some forest conditions at under certain climate conditions, but they are not a “cure-all” replacement for logging methods.  They can be difficult to control and even under ideal conditions are not without their own set of adverse water quality impacts.  In many instances logging, or mechanical harvesting, can be less detrimental to water quality and sustained yield from the watershed than fire.  There are effective BMPs governing logging as well as other valid conservation uses of the forest lands.  It is the responsibility of the land use managers to make sure that protecting water quality and watershed areas is among the highest priorities in Colorado and that appropriate BMPs are applied to all forest uses to achieve the necessary levels of protection.
Strive to put “forest management” back into the hands of professional forest managers and take it out of the hands of extreme special interests that have no obligation to serve the majority of the public that depend upon the federal lands for its safety and well-being.
Politically and financially support best management practices for all lands within the watershed.

## On-going Concerns and Questions

- What if there isn’t enough water to duck?
- What are the post-fire impacts on the receiving reservoirs and streams?
- How long will it take to return to “normal”?
- Are there forest management practices that will produce a healthy on-going balance that supports sustained yield and protects water quality?

**Notes:**
What if the available water supply becomes so limited that temporarily closing the intake to “duck” the spike of contaminants is not possible?
What are the long-term impacts of increased nutrient loads on the receiving reservoirs?
What are the long-term impacts of increased sediment loads on the receiving reservoirs and streams?
How long will it take to return to “normal” as vegetation and erosion  stabilizes?
Can the future risk of catastrophic fire be reduced through improved forest management practices?

## On-going Concerns and Questions

- Should federal land use management agencies be held accountable for their forest management decisions in civil proceedings related to public health issues and/or federal laws governing water quality?

**Notes:**
If a public water system were to violate EPA Clean Water Act or Safe Drinking Water Act regulations as a result of having to try to cope with contaminants resulting from inappropriate forest management practices, would the land management agency also culpable for lawsuits brought against the water supplier?
Would it be appropriate to legally and socially treat national land use management practices the same way we treat private and local government management practices when it comes to issues of public health and compliance with environmental protection laws.  I.e. if forest land management practices result in the accumulation and sudden release of mercury into the atmosphere and water, as in a natural or prescribed burn, should the land use manager/s be held to the same standard as a corporation, local government, or individual citizen?