Updated Map

We have compiled the sites which we tested onto one map. Although we have already drawn conclusions from our research, this map shows the landscape. This illustrates that Mill Creek is part of a much larger ecosystem, and when the pollution enters it, the pollution will eventually end up in the Pacific Ocean because of the connectivity of waterways. 

Conclusions from Research

After doing some research on the pH tests, we are unable to determine anything about the overall quality of Mill Creek based purely on data we collected. The pH tests were inconclusive in that they did not show anything abnormal about the creek, the pH levels were where they were to be expected, approximately between 6.5 and 8.5. In order to gain a fuller understanding, we would need to also conduct tests for fecal chloroform, dissolved oxygen, turbidity, temperature, nitrates, and phosphorus. The more tests we conduct, the more we understand which pollutant is leading to further problems with the water quality. 

However, through our research, we have still determined that Mill Creek is in danger of suffering from stormwater pollutants. 

One of the most concerning locations for stormwater drainage is directly next to Mill Creek. Walla Walla has been implementing different ways to help control runoff, such as the creation of permits needed for effluent, as well as systems of catching and infiltrating the polluted runoff to keep it from directly entering the water. However, because none of these systems are near Mill Creek, 

it seems as though the best solution right now is to put some of these into place. This would include adding catch basins, detention basins, dry wells, infiltration ponds, infiltration trenches, and oil/water separating systems.
It is hard to reduce the pollutants that are already in Mill Creek, but adding a few of these stormwater runoff safety systems would help Walla Walla from worsening the quality of Mill Creek in the future.

-Marra and Riley

Specific Pollutants of Concern in Walla Walla

The Walla Walla Public Works Department released the specific locations which they deem to be the most concerning regarding stormwater pollution. These locations have extra leakage of toxins, and would be more harmful than other areas.

This is the list of the locations, as well as the pollutants of concern within each spot.

The County Garage is the location with the most concern regarding Mill Creek, seeing that it is directly adjacent to the water. The tests conducted at Site 1 were in fact taken while standing on the County Garage grounds. 

The Walla Walla Public Works Department has also released data which lists the different sources of pollutants in Walla Walla with regards to the specific locations and how much of a concern they are. 

Based on this information, we notice that the County Garage's primary concerning activities are vehicle maintenance and vehicle storage. The toxins may leak out of cars if they sit for long periods of time, then eventually make their way to Mill Creek since it is just a few feet away. 

Because the government is aware that the County Garage is a trouble spot, I am questioning why they do not implement some sort of protection. As shown on a previous map, there are no collection or infiltration systems established on Mill Creek. The Walla Walla Public Works Department should put some sort of system in place next to the County Garage, because, due to its close proximity and its concerning pollutants, it could be detrimental to the health of Mill Creek. 

Sources

Walla Walla Public Works Department, (2011). Walla walla county stormwater operations and maintenance plan . Retrieved from website: http://wwcountyroads.com/Docs/Stormwater-operations-Maintenance-Plan.pdf

Using Native Plants to Help Control Runoff

One easy way to keep pollutants from running off into waterways, such as Mill Creek, is to plant native plants and grasses near the water. 

As the runoff goes downhill towards the water source, if there are plants near the waters edge, the pollutants can infiltrate there, rather than flow directly into a river or lake. Many studies have been done which have concluded that using native plants for this job is more beneficial, their roots have adapted to the environment, and they will be able to allow for more percolation of water. 

Additionally, xeriscaping, the act of using native plants, is beneficial towards the environment because it also uses less water. This is particularly beneficial in desert areas, where water is scarce. Plants which are native to areas are meant to use the water available to them; plants in the desert don't require a lot of water, while plants in western Washington, where there is a lot of precipitation, require more. 

Fortunately, Mill Creek is lined with many plants, particularly upstream of town. In town, because the creek is confined to a small canal, there are no plants, pure concrete. This is not ideal. However, the plants on the edges before town, and a few plants after town, are beneficial because they help especially with the problem of farm runoff, which was already discussed in an early blog post.

This photo, as well as the one at the beginning of this post, are examples of two grassy plants found alongside Mill Creek. The plant above was found at Site 2, while the grasses below were found near Site 1.

Sources: 

United States Environmental Protection Agency. (2012, June 26). Landscaping with native plants. Retrieved from http://www.epa.gov/greenacres/conf12_04/conf_knwldge.html

Research on Stormwater Collection in Walla Walla

Now that we have been able to see that stormwater not only exists, but is also a concern in Walla Walla, I have been directing my research towards the sources of pollution in our own town, as well as the different systems for catching the stormwater.

Here is a map, found from the Walla Walla Public Works Department, which shows all the different locations of stormwater collection in Walla Walla.

In contrast, here is a map of Walla Walla, with Mill Creek highlighted.

It is certainly beneficial that Walla Walla has established so many different conveyance systems for the stormwater, but it is also causing a problem because there are none of these systems for collection close to Mill Creek.

The possible reason for this is tying back to my ideas regarding distribution of wealth in Walla Walla. When discussing labeling the storm drains to show that they go to the water sources, I hypothesized that the labels were only in a certain area because they could afford to put them up. This same area, south of the Whitman College campus, is the same area that, according to the first map, has a huge portion of the stormwater conveyance systems. Is it, once again, because they can afford them?

None of the stormwater collection or filtration service are in play on Mill Creek until downstream of town. Mill Creek, known for its contamination, should have more of these throughout Walla Walla.

Sources:
Walla Walla Public Works Department, (2011). Walla walla county stormwater operations and maintenance plan . Retrieved from website: http://wwcountyroads.com/Docs/Stormwater-operations-Maintenance-Plan.pdf

Farm Runoff

Both upstream of downtown Walla Walla and after the city, Mill Creek is lined by farms. The farm fence pictured here was less than 30 feet away from the water, just east of Walla Walla Community College. 

There are lots of plants around the edge of the water, acting as a barrier between the runoff from the farms and the creek. What could the consequences be if those did not exist? In many areas, they don't have proper filtering systems for runoff from agriculture before it reaches a water source. 

Agriculture runoff is considered a nonpoint source pollutant because it come from a wide area of land. In 2003, the Environmental Protection Agency established a number of measures to be used to help control this runoff. These documents can be found here:

http://water.epa.gov/polwaste/nps/agriculture/agmm_index.cfm

There area  variety of additives in the runoff from farms. They include pesticides, herbicides, and fertilizers. Pesticides and herbicides create problems for obvious reasons: they are toxic and can often times kill the organisms living in the water. Fertilizer is a more complex pollutant. The fertilizer is comprised of nitrogen, phosphates, and potassium, in a variety of proportions. These act as nutrients to the plants on the farms, and continue to act as nutrients to plants as they are brought into the rivers from runoff. This gives algae and other plants in the water extra growing ability. Bacteria begin to eat away at the algae, and in doing so they also use up the dissolved oxygen in the water. 

The main effects of this situation are an increase in turbidity, due to the extra plant growth and the bacterial waste, and a lower dissolved oxygen content. 

One of the easiest and most effective ways to prevent this runoff is to plant a barrier between water (such as lakes and rivers) and farmland. It is important to use native plants because they will have the ability to allow for percolation of the runoff, instead of having the runoff sit in the top layer of the soil. 

Sources:

United States Environmental Protection Agency. (2013, September 09). Water: Polluted runoff. Retrieved from http://water.epa.gov/polwaste/nps/agriculture.cfm

Birds: Both adding to the pollution and suffering from it.

Like these Canadian Geese, birds in the area flock to Mill Creek because it is such a large water source in our desert-like area. 

After seeing hundreds of birds living around Mill Creek while conducting pH tests, I wanted to learn all about how these birds were being harmed by the pollution in the creek. However, to my surprise, the birds are actually adding to the pollution in many cases. 

Yes, the birds are still being negatively effected by the pollution in the water. The toxins that runoff into the creek will bioaccumulate and be consumed by the birds, where the toxins will then living and accumulate in their systems. Because many of the pollutants are carcinogenic, they have lots of negative bodily effects on the birds and the birds' reproduction.

However, by flocking to these areas, the birds are also creating a problem in the water. Bird feces acts the same way as fertilizer in the water. Bacteria eat the organic waste, and during this process they also use a significant amount of the oxygen in the water. Lower dissolved oxygen in the water leads to other aquatic animals not having sufficient oxygen to survive. Bird waste is considered an "organic macro-pollutant" in water sources. 

So, while I still do pity these little geese for living in a polluted area, they aren't exactly helping. Even though large portions of the organic waste in Mill Creek come from other sources, such as fertilizer from farm runoff (which will later be discussed), the birds here aren't making things better. 

Sources:

Gobel, P., Dierkes, C., & Coldewey, W. G. (2007). Storm water runoff concentration matrix for urban areas.Journal of Contaminant Hydrology, 92(1-2), 26-42. Retrieved from http://www.sciencedirect.com/science/article/pii/S0169772206001938