Can Infrastructure Spending Help Iowa’s Polluted Rivers?

by Dan Haug | Jan 1, 2024

The display department for the plans. If you've read Douglas Adams, you'll appreciate the joke.

“But look, you found the notice didn’t you?”
“Yes,” said Arthur, “yes I did. It was on display in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying Beware of the Leopard.”

– Douglas Adams, The Hitchhiker’s Guide to the Galaxy

I was reminded of this scene after spending a long day cross-referencing the Raccoon River TMDL (a pollution budget for nitrate and E. coli) with permits and monitoring data for wastewater treatment plants. In this case, I suspected that polluters were getting away with something, but I’ve had just as much trouble finding information when I wanted to document a success story.

Effluent limits for nitrogen are not strict. Wastewater treatment plants and meatpacking plants in the Raccoon River watershed routinely discharge treated wastewater with nitrate 4-6x the drinking water standard. Why is this allowed? The 2008 Raccoon River TMDL capped pollution from point sources at the existing level, rather than calling for reductions. Due to limited data, the wasteload allocations were an over-estimate, assuming maximum flow and no removal during treatment.

That’s all above board, but someone else at the DNR went a step further. Wasteload allocations in the TMDL were further inflated by a factor of two or three to arrive at effluent limits in the permits, using a procedure justified in an obscure interdepartmental memo. The limits are expressed as total Kjeldahl nitrogen, even though the authors of the TMDL made it clear that other forms of nitrogen are readily converted to nitrate during treatment and in the river. In short, the limits in the permit allow more nitrogen to be discharged than normally comes in with the raw sewage!

For example:

The Storm Lake sewage treatment plant has an effluent limit of 2,052 lbs/day total Kjeldahl nitrogen (30-day avg). Total Kjeldahl nitrogen in the raw sewage is around 1000 lbs/day.
The Tyson meatpacking plant in Storm Lake has an effluent limit of 6,194 lbs/day total Kjeldahl nitrogen (30-day avg). Total Kjeldahl nitrogen in the raw influent is around 4,000 lbs/day.
I also checked a permit affected by the (now withdrawn) Cedar River TMDL. Same story. The Cedar Falls sewage treatment plant has an effluent limit of 1,303 lbs/day total nitrogen (30-day avg). Average total nitrogen in the raw sewage is between 1000-1500 lbs/day.
Confused about the units? That may be deliberate. Total Kjeldahl nitrogen includes ammonia and nitrogen in organic matter. Nitrogen in raw sewage is mostly in these forms, which need to converted to nitrate or removed with the sludge in order to meet other limits and avoid killing fish. Nitrogen in treated effluent is mostly in the form of nitrate. At the Tyson plant, the effluent leaving the plant has around 78 mg/L nitrate, versus 4 mg/L TKN, but figuring that out required several calculations. At smaller plants, the data to calculate nitrate pollution isn’t even collected.

As part of the Iowa Nutrient Reduction Strategy, large point source polluters are supposed to evaluate the feasibility of reducing nitrate to 10 mg/L, and phosphorus to 1 mg/L. Tyson did a feasibility study for phosphorus removal, and is now adding new treatment to its Storm Lake plant. However, it is not required to evaluate or implement further nitrogen reduction, “because it is already subject to a technology-based limit from the ELG.” This federal Effluent Limitation Guideline was challenged in court by environmental groups this year, and is now being revised by the EPA. It allows meatpacking plants to discharge a daily maximum of 194 mg/L total nitrogen!

Fortunately, all this creative permitting has little impact on the cost and safety of drinking water in the Des Moines metro. According to research in the TMDL, point sources only account for about 10% of the nitrogen load, on days when nitrate in the Raccoon River exceeds the drinking water standard. However, the figure is much higher (30%) for the North Raccoon River. I started looking at permits and effluent monitoring because I was trying to explain some unusual data from nitrate sensors, brought to my attention by friends with the Raccoon River Watershed Association. During a fall with very little rain (less than 0.04 inches in November at Storm Lake), nitrate in the North Raccoon River near Sac City remained very high (8 to 11 mg/L). The two largest point sources upstream of that site can easily account for half the nitrogen load during that period.

I was glad to be able to solve a mystery, and hope that this investigation can lead to some tools and teaching materials to help others identify when and where point sources could be influencing rivers. The load-duration curves in the 200-page Raccoon River TMDL are very good, but some people might benefit from something simpler, like this table. In general, the bigger the facility, the smaller the river, and the drier the weather, the more point sources of pollution can influence water quality, and the more wastewater treatment projects can make a difference.

Spreadsheet for estimating impact of wastewater.

I made this table to estimate how biological nutrient removal in Nevada and Oskaloosa (about 1 MGD each) could improve water quality in the South Skunk River (about 1000 cfs on average near Oskaloosa, but there could be greater benefit in tributaries, or when rivers are lower).

In this work, I’m supported by partners around the state and a grant from the Water Foundation. The project (Movement Infrastructure for Clean Water in Iowa) focuses on building connections and shared tools around water monitoring, and will continue through this spring and summer. The funders’ interest is in helping the environmental movement make the most of the “once-in-generation opportunity” presented by the Inflation Reduction Act and the Bipartisan Infrastructure Law. This fiscal year, the Bipartisan Infrastructure Law is adding $28 million to Iowa’s Clean Water State Revolving Fund, which provides low-interest loans to communities to replace aging sewer systems and treatment plants. Can that infrastructure spending help Iowa’s polluted rivers? We won’t know for sure without better use of water quality data, and greater transparency in state government.

Five Stages of Watershed Awareness

by Dan Haug | Oct 4, 2023

October is Watershed Awareness Month, by proclamation of Story County Conservation Board and city councils in Ames, Nevada, and Gilbert. Okay, so what exactly do we want people to be aware of? I would suggest the following progression…

Stage 1: What’s a watershed? Who cares?

A watershed is the land area that drains to a common outlet. Imagine a river valley between two mountain ridges. Now replace that mental image with gentle hills–we’re in Iowa. But more important than knowing the definition is understanding why it’s important: because water flows downhill, actions on land can have consequences for downstream water bodies.

Perhaps the best illustration of this principle is an incident from 2020. Following a power outage, some Hy-Vee employees in Ankeny poured 800 gallons of spoiled milk down a storm sewer, turning the nearby creek white, killing 2,000 fish, and costing their employer almost $25,000 in fines and restitution. The silver lining of this boneheaded decision was that it made the news and reminded many Iowans that yes, storm sewers drain to rivers (usually without any treatment) and so we should think twice about what we pour or let wash in. The same principle applies to ditches, gullies, and drainage tiles.

Want a more positive framing? Watch this one-minute video we created with the City of Ames about the South Skunk River, and how cities and farms in the watershed can make a difference.

Stage 2: What’s my watershed(s)?

It’s one thing to know that my actions could (in principle) help or harm some downstream water body. It’s another thing to know that what goes down my neighborhood storm drain ends up in Ioway Creek at Brookside Park, a place where I’ve taken my kids to play. In 2018, we partnered with Story County Conservation to put up watershed and creek signs, in hopes that more people make those kinds of connections.

Creeks flow to rivers and rivers flow to the sea (except in endorheic basins) so we live in multiple, nested watersheds. A convenient way to represent this is with the US Geologic Survey’s Watershed Boundary Dataset, which has mapped American watersheds at six levels and assigned them each a unique hydrologic unit code (HUC). You can look up your “watershed address” with our interactive map. For example, that grocery store in Ankeny is in the lower Fourmile Creek watershed, within the watershed of Red Rock Lake, within the watershed of the Des Moines River, and within the upper part of the giant Mississippi River basin.

Stage 3: Who are the other people in my watershed?

One reason to learn which watershed you live in is to connect with other people who are concerned with flooding, water quality, fisheries, and recreation.

Twenty-eight watersheds in Iowa have a Watershed Management Authority with representatives from local governments in the watershed (cities, counties, and soil and water conservation districts) who might collaborate on water quality or flood control projects. Fourmile Creek WMA is one of the more active WMAs; its member jurisdictions pooled money to hire a watershed coordinator who can work with farmers and landowners. In some watersheds, farmers and landowners have access to additional cost-share programs or receive higher priority when they apply.

In some watersheds, a volunteer group, land trust, or other non-profit organization organizes projects to protect the water or raise public awareness. For example, the lake at Ada Hayden Heritage Park in Ames has a friends group, while the Raccoon River has a volunteer Watershed Association in addition to three WMAs.

Caveat

Unfortunately, I’m not aware of any central clearing house where one can find out what groups and projects are active in your watershed. I’m also not aware of any plans by state leaders to provide WMAs with stable funding or to delegate to them any powers that would help them accomplish their tasks. Watershed projects tend to be grant-funded (and thus short-lived) and watershed coordinator jobs often have high turnover.

Stage 4: What are the issues in my watershed?

Some watersheds have management plans (like this one for Fourmile Creek) that identify creek- or lake-specific problems and solutions. However, in many cases, the data needed to evaluate a problem and track progress toward solutions is missing until volunteers, universities or local government step up to do monitoring.

Knowing which issues go with which watershed can help us prioritize and find solutions.

Not every stream has the right conditions to support a trout fishery (like Bloody Run in Clayton County).
Not every stream has a history of destructive floods (like Fourmile Creek in Polk County).
Not every lake or reservoir has suffered from toxic algae blooms (like Brushy Creek Lake in Webster County).
Not every river is deep enough and has access for canoeing (like the South Skunk River in Story County).
Not every river affects the supply and safety of drinking water for thousands of people (like the Raccoon and Cedar rivers).

Stage 5: How big are the problems and solutions in my watershed?

The most difficult thing to understand about a watershed is the scale. It helps to have some familiar reference points. Here are some of mine. (I’ve used an app that makes it easy to delineate a watershed for any point of interest. The area is rounded to the nearest 100 acres.)

1,000 acres: Creek at Tedeco Environmental Learning Corridor, Ames.
5,900 acres: Peas Creek at the Ledges State Park.

At the HUC12 scale, most creeks are too wide to jump across, but shallow enough to wade. Watersheds are small enough to fit in one county.

14,100 acres: Walnut Creek at Neil Smith National Wildlife Refuge
24,000 acres: Bloody Run at Marquette.
56,800 acres: Fourmile Creek at Sargent Park in Des Moines.

At the HUC10 scale, it might be called a creek, but it often has enough water to float a canoe, and watersheds usually cross a few county and city lines.

132,700 acres: Ioway Creek at Brookside Park in Ames.
173,500 acres: Maquoketa River at Manchester.
209,300 acres: South Skunk River at River Valley Park in Ames.
356,100 acres: Rathbun Lake

At the HUC8 scale and beyond, the rivers are big and the watershed meetings can involve many jurisdictions and long drives.

586,400 acres: Floyd River at Sioux City
1,285,200 acres: North Raccoon River at Squirrel Hollow Park in Jefferson
2,306,200 acres: Racoon River at Waterworks Park, Des Moines
3,733,300 acres: Des Moines River at Saylorville Reservoir
97,191,700 acres: Mississippi River at Dubuque

For each of these watersheds, you’d need to plant about a third of the cropland to cover crops to reduce nitrogen and phosphorus in the stream by 10%. Most watershed plans will include more ambitious long-term goals and more complicated scenarios to achieve them, but this is a handy benchmark for thinking about the scale of change needed. Reaching the 1/3 mark for cover crops in a watershed would be good progress toward our 45% nutrient reduction goals and could produce a big enough improvement in water quality in the stream that we could conceivably measure it, though maybe not with test strips (i.e. from 10 to 9 mg/L of nitrate, from 0.40 to 0.36 mg/L of total phosphorus).

I don’t mean to discourage anyone, but I’m not aware of any watershed project in Iowa that has achieved success on this scale.

Appreciating Water and Wastewater Workers

by Dan Haug | Aug 23, 2023

Water and Wastewater Workers of Iowa Week!

In August the governor issued a proclamation recognizing these essential workers. I’ve had the privilege to get to know some of the folks who make sure the water in the tap is clean enough to drink, that the wastewater we flush doesn’t contaminate rivers, and that the storm sewers drain the streets without causing downstream flooding or pollution.

Ames WPCF Superintendent Tyler Ver Meer at an open house. Note the watershed map!

Sure, these kinds of jobs can involve reading meters, reviewing construction documents, doing inspections, and testing water quality. But it can also involve live-trapping turtles to stop them from damaging an expensive baffle curtain in a wastewater treatment lagoon by sitting on it (Tim Mattingly, City of Gilbert). It can involve handing out rubber duckies and demonstrating a flood model for kids at a school science night (Liz Calhoun and Jake Moore, Ames Public Works). It can involve taking time out of a busy schedule to attend meetings about watersheds and water monitoring (thanks to staff from Ames, Gilbert, Nevada, Roland, and Huxley who have come to mine). And it can involve canceling that meeting and rushing to the sewage treatment plant to help contain a spill when a valve breaks (this happened once to Ashley Geesman and Neil Weiss, Ames Water & Pollution Control).

I’ve been getting even more appreciation for wastewater treatment plants and the people who run them as I’ve researched and filmed Facts 31-35 of our weekly video series, “The Clean Water Act: 50 Years, 50 Facts.”

At a basic level, sewage treatment involves harnessing microbes to break down organic matter that would otherwise consume the oxygen in the water as it decomposes, and improving water clarity by allowing the solid material to settle out. Widespread secondary treatment of wastewater has taken care of some of the worst pollution that was affecting America’s rivers when the Clean Water Act was passed in 1972. But processes aimed at TSS (a metric of water clarity)and CBOD5 (a metric of oxygen consumption) doesn’t always get various forms of nitrogen (nitrate and ammonia), phosphorus, E. coli bacteria, or chloride down to an acceptable level. We’ve seen that in some our water monitoring results.

However, communities in Iowa continue to invest in improvements to their sewage treatment systems. NPDES permits have to be renewed every five years, and additional requirements come into play when a facility is renovated to increase capacity or replace deteriorating infrastructure. Some examples from the South Skunk River watershed include:

The City of Nevada is building a new plant (to be completed in 2024) that will include systems to remove additional nitrogen and phosphorus. Ames, Oskaloosa, and Newton also are planning nutrient removal systems.
The City of Ames spends over $3 million each year to repair or replace aging sanitary sewers.
The City of Gilbert installed an extra stage to better treat ammonia during the winter months.
A homeowner’s association near Gilbert is switching its water source to reduce the need for water softeners and the chloride (salt) pollution that comes with it.
Over the last decade, UV disinfection systems to address fecal bacteria have been installed in sewage treatment plants in Ames, Newton, Story City, Huxley, Roland, Gilbert, Cambridge, and a neighborhood association. Colfax uses chlorine disinfection. Oskaloosa, Maxwell and Nevada have upgrades in the works.

However, if non-point sources of pollution like agricultural runoff and stormwater aren’t addressed, cities and towns reach a point of diminishing returns where sewer rates are going up but water quality in the river isn’t getting noticeably better. That’s why it’s exciting to see more water utilities breaking out of traditional silos and partnering with farmers on conservation projects in their watersheds.

(Edit 2023-12-29: The numbers I was using are potentially confusing and not relevant to the point I was making, so I have deleted them. According to models used for the Iowa Nutrient Reduction Strategy, point sources of pollution like wastewater account for 5% of the nitrogen load and 12% of the phosphorus load during the 2006-2010 benchmark period. The South Skunk River as a whole has a similar breakdown, but the stretch between Ames and Colfax has a higher percentage of pollution from point sources.)

Drainage “Improvements”

by Dan Haug | Jul 31, 2023

Sometimes, cutting down trees and moving earth along a stream is necessary to ensure adequate drainage for crops or prevent destructive flooding. Sometimes, it is necessary to reconnect a stream with its floodplain after centuries of hydrologic alteration, erosion and siltation. Sometimes cutting down trees and moving earth isn’t necessary at all, or could be done in a much smaller footprint. You can’t always tell which is which unless someone who knows the land goes to the trouble of reading dull engineering reports and attending dull meetings.

In 2020, a group of landowners successfully petitioned to reclaim trusteeship of their drainage district from the Clay County Board of Supervisors in order to block what they see as a “huge, costly, and environmentally destructive improvement on Pickerel Run.” I share this story, related by Steve Swan, in hopes it encourages more people to go to the trouble.

-Dan

Drone footage of Pickerel Run (source: pickerelrun.com)

By Steve Swan

Pickerel Run is a tributary of the Little Sioux River, located east of Spencer. Drainage District #37 was formed in 1917 to improve drainage by dredging, straightening and widening parts of this stream. Pickerel Run is unusual in that it has not silted in and in many places is almost twice as wide as originally constructed, and therefore is capable of carrying more water than the original design. These days, fewer farmers are grazing livestock and trees have grown up along the banks. Trees can impede drainage when they fall into the channel or when they grow too close to the normal waterline, so some need to be removed, but most are not causing problems and seem to be stabilizing the bank.

Our understanding of the situation was not reflected in the 2018 report by Bolton & Menk, which took several years to complete and cost over $100,000. Landowners were oblivious to what was going on until the report was done and a $3.6 million improvement was recommended, which would remove all trees within a 300-foot work area, level the spoil banks, and dredge the stream. The engineers were sure that 55,000 acres of land upstream could be annexed once the project was completed and be made to pay a significant portion of the bill. This proposal came at a time when cash rents in Clay County had been falling for several years.

The highlighted stretch of Pickerel Run in included in D.D. 37

In many counties, the county supervisors act as trustees for the drainage districts. Iowa code is clear that trustees are obligated to make repairs if necessary, desirable and feasible. However, Iowa’s drainage laws (Section 468) make easy for engineering firms to initiate a massive drainage project—a single signature on a petition—and very difficult for the landowners who must ultimately pay for the project to stop it once it gets rolling. The remonstrance process requires representation of 70% of the acres and 50% of the owners to vote against the project, with parcels held the government or still in the name of a deceased owner defaulting to count in favor of the project.

Once they found out what was happening, landowners began the remonstrance process, and were assured that time would be given for owners to register their opposition of the project. The supervisors called the remonstrance vote early and an initial reading of the results showed a shortfall of the votes needed to stop the project, but the spreadsheet used to calculate the remonstrance contained many errors. A lawsuit ensued.

Realizing that the supervisors were going to stay their course, landowners took advantage of the law and forced a vote to make the trusteeship of the drainage district private. There were more irregularities and another lawsuit for which our landowners had to pay both sides.

Eventually landowners won control of Pickerel Run/DD#37. After the successful privatization of our district, the “drainage industry” successfully lobbied for an amendment to Iowa Code 468 making it more difficult for other districts to follow suit.

Since the landowner trustees have taken office, a plan has been developed to keep water flowing while still maintaining some of the wonderful habitat that had developed over the past 100 years. Some trees have been cut, but many have been saved. Money is being spent, but much less than what would have been spent. The bed of the creek, which supports five species of native mussels and seventeen species of fish, has been spared a clean sweep by big earth moving equipment. The banks are still a haven to a multitude of wildlife species, including a great blue heron rookery, bald eagles, countless waterfowl, and deer in a sea of corn and soybean fields.

Iowa is a farm state and water does need to drain. Perhaps the simplest and best way to ensure that drainage projects are only done when truly needed would be to amend the threshold required for a remonstrance to stop a project.

My dream would be that all the groups that support quality of life in Iowa would become aware how important Iowa Code Section 468 is to life in Iowa and come together to lobby and oppose self-serving engineering firms in the drainage industry that are mainly looking for additional projects to generate revenue, regardless of damage done.

Tallgrass Prairie – A Butterfly’s View

by Dan Haug | Jul 13, 2023

The tallgrass prairie once covered 170 million acres, and at the 2023 North American Prairie Conference, I was reminded of that continental scale. Between assisting presenters with technology, I heard sessions about protecting orchids in the aspen-prairie parkland of Manitoba, time lapse photography along the Platte River in Nebraska, surveying insects in Alabama’s “Black Belt”, restoring spring wildflowers on the Kankakee Sands of Indiana, and building out the native seed supply chain in South Dakota, as well as lots of good information from friends and colleagues in Iowa. The following are a few insights I picked up from the conference, written from a butterfly’s perspective.

Hi, I’m a monarch butterfly (Danaus plexippus). Like the meadowlark, I continued to thrive in Iowa long after the prairie was broken. For me, the tipping point was when GMO soybeans and copious use of herbicides replaced “walking the beans” as a method for weed control. No more milkweed in farm fields! Like the meadowlark, I’m a strong flier and not too picky about my habitat, but I’ve got two pairs of eyes (two compound eyes and two ocelli) so my perspective is a little different!

Monarchs on meadow blazingstar, photo credit Monarch Butterfly Garden

For me, it’s all about the forbs—broad-leaved herbaceous plants. I know, you can’t have grassland without grasses, but I need milkweeds to feed my caterpillars and nectar-producing flowers to drink. I’m visit whatever flowers are blooming (I’ll even use non-native forage plants like red clover and weeds like musk thistle) but since Dr. Benedict and his students are asking, yes, I do have some favorites. In addition to milkweeds, I’m partial to plants in the sunflower family, which have heads packed with nectar-producing, short tubed flowers that make for easy sipping. At the Central College prairie, compassplant (Silphium laciniatum) is my top choice, but that’s just because you don’t have any meadow blazing star (Liatris ligulostylis). As native plant nurseries and seed producers can attest, we monarchs go nuts for that!

In some remnant prairies, we’ve seen the forbs get crowded out by aggressive grasses like big bluestem and switchgrass. It’s even worse in restored prairies that used too much grass in the seed mix—we see this with older CRP plantings. On the other hand, a seed mix without any native grasses won’t have all the functions of a prairie and won’t hold up well against invasive weeds. In an intact prairie, the big warm-season grasses are important, but they’re kept in check by a combination of fire and grazing—the fire makes the grass green up and then the bison chow down! Hemiparasitic plants like lousewort (Pedicularis lanceolata) and bastard toadflax (Commandra umbellata) also set back the grass by sending a modified root into the grass roots and sucking out their juices. Prairie isn’t just a collection of native plants, it’s a web of relationships!

Few reconstructed prairies have bison or hemiparasitic plants, so check out this NRCS publication for other ideas to increase forb diversity in grass-dominated stands.

If you’re starting from scratch, be sure to use a seed mix like CP25 or CP42 that includes plenty of native flowers. We’re happy to learn that over 600,000 acres in the Conservation Reserve Program (CRP) have been planted with these mixes.

Iowa can be an inhospitable place for an insect, but thanks in large part to the efforts of the Tallgrass Prairie Center at UNI and the Iowa DOT’s Living Roadway Trust Fund, we have a better supply of native seeds than many other states, and many miles of roadside ditches planted to prairie. Next step, find some more room for prairie plantings on farms and in cities!

NAPC field trip to Neil Smith Wildlife Refuge

This article is based on sessions presented by Laura Jackson (University of Northern Iowa), Tom Rosburg (Drake University), Russell Benedict (Central College), Justin Meissen (University of Northern Iowa), Brian Wilsey (Iowa State University), and James Cronin (USDA-NRCS).

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