Nutrient Runoff is Killing American Waters and Voluntary Actions Aren’t Working

Donald Scavia

Lake Erie, 2011—A satellite image captures the great lake's worst toxic algae bloom in decades.

Sum­mer is the sea­son for harm­ful algae blooms in many U.S. lakes and bays. They occur when water bod­ies become over­loaded with nitro­gen and phos­pho­rus from farms, water treat­ment plants and oth­er sources. Warm water and lots of nutri­ents pro­mote rapid growth of algae that can be tox­ic and poten­tial­ly fatal to aquat­ic life and people.

Even­tu­al­ly algae set­tle to the bot­tom and decay, deplet­ing dis­solved oxy­gen in the water, cre­at­ing hypox­ia—“dead zones” where oxy­gen lev­els are low enough to kill fish.

As a senior sci­en­tist at the Nation­al Oceano­graph­ic and Atmos­pher­ic Admin­is­tra­tion (NOAA) between 1975 and 2003, I devel­oped annu­al hypox­ia fore­casts for the Chesa­peake Bay and the Gulf of Mex­i­co — two of our nation’s water bod­ies most harmed by these blooms. At the Uni­ver­si­ty of Michi­gan, I helped devel­op harm­ful algae bloom fore­casts for Lake Erie and con­tin­ue to work with pub­lic and pri­vate orga­ni­za­tions on these issues.

States around Lake Erie and in the Mis­sis­sip­pi Riv­er basin, which drains to the Gulf of Mex­i­co, have been try­ing to reduce nutri­ent pol­lu­tion for years. They rely pri­mar­i­ly on vol­un­tary steps, such as offer­ing grants to farm­ers to take steps to pre­vent fer­til­iz­er from wash­ing off their fields.

In con­trast, states around the Chesa­peake have had more suc­cess with a fed­er­al­ly enforced plan that can impose manda­to­ry actions across the bay’s 64,000-square-mile water­shed. From my per­spec­tive, when we com­pare these two approach­es it is clear that vol­un­tary mea­sures are not even mak­ing mod­est dents in nutri­ent pollution.

This year’s forecasts

This year’s Lake Erie harm­ful algae bloom fore­cast has a sever­i­ty index of 7.5 on a scale of 1 to 10. This is com­pa­ra­ble to the three largest blooms since 2011, includ­ing one that made the city of Toledo’s tap water unus­able for three days in 2014. The algae pro­duced microsystin — a tox­in that can pro­duce effects from mild skin rash­es to seri­ous ill­ness or death.

The Gulf of Mex­i­co fore­cast pre­dicts an 8,185-square-mile dead zone — more than four times the goal set by an inter­gov­ern­men­tal task force. This will be the third-largest Gulf of Mex­i­co dead zone since mea­sure­ments began 32 years ago.

The Chesa­peake fore­cast pre­dicts a 1.9‑cubic-mile hypox­ic region — near­ly the vol­ume of 3.2 mil­lion Olympic-size swim­ming pools. This is much larg­er than goals reflect­ed in recent poli­cies. Nonethe­less, at least the Chesa­peake is mov­ing in the right direc­tion. The amount of nutri­ents flow­ing into the bay is start­ing to decline.

The Chesa­peake Bay water­shed cov­ers more than 64,000 square miles in parts of six states and the Dis­trict of Colum­bia. (Map: Kmuss­er / Wikipedia)

The long quest to clean up Lake Erie

Lake Erie first suf­fered from heavy nutri­ent pol­lu­tion in the 1960s. The Clean Water Act of 1972 trig­gered a remark­able cleanup. Nutri­ents, pri­mar­i­ly from point (dis­creet) sources like sewage treat­ment plants, were cut in half, and the lake respond­ed quick­ly.

But harm­ful algae blooms and hypox­ia resur­faced in the mid-1990s, prob­a­bly because flows into the lake of a form of phos­pho­rus that is read­i­ly used by algae tripled. The dead zone set a new record in 2012, and harm­ful algae blooms set records in 2011 and 2015. Even if blooms do not become tox­ic, they can have dev­as­tat­ing effects. For exam­ple, the 2011 harm­ful algae blooms on Lake Erie cost the region near­ly $71 mil­lion in dimin­ished prop­er­ty val­ues, water treat­ment, and lost tourism rev­enues and recre­ation­al opportunities.

In response, the Unit­ed States and Cana­da nego­ti­at­ed new phos­pho­rus load­ing tar­gets that call for a 40 per­cent reduc­tion from 2008 lev­els. Ontario, Ohio, Michi­gan, Indi­ana, Penn­syl­va­nia and New York are devel­op­ing domes­tic action plans to meet those targets.

Now how­ev­er, 71 per­cent of nutri­ents enter­ing Lake Erie are from non-point sources—main­ly from agri­cul­ture. Non-point source pol­lu­tion comes from dif­fuse sources, such as fer­til­iz­er wash­ing off of farms and lawns, so it is hard­er to control.

The Unit­ed States con­tributes over 80 per­cent of Lake Erie’s total phos­pho­rus load. In sum, major load reduc­tions will have to come from agri­cul­ture, most­ly from U.S. farms.

Phos­pho­rus loads to Lake Erie. (Info­graph­ic: Mac­coux et al. Jour­nal of Great Lakes Research 42 (2016) 1151 – 1165)

How effec­tive are vol­un­tary measures?

Gov­ern­ments gen­er­al­ly are averse to impos­ing envi­ron­men­tal reg­u­la­tions on farm­land. As a result, most action plans for Lake Erie rely on vol­un­tary, incen­tive-based pro­grams to address nutri­ent loss from agri­cul­tur­al lands.

But in the Mis­sis­sip­pi Riv­er basin this approach has failed. In spite of more than 30 years of research and mon­i­tor­ing, over 15 years of assess­ments and goal-set­ting, and over $30 bil­lion in fed­er­al con­ser­va­tion fund­ing since 1995, aver­age nitro­gen lev­els in the Mis­sis­sip­pi have not declined since the 1980s.

The task force lead­ing this effort recent­ly extend­ed the dead­line for its goal of a 1,930-square-mile dead zone from 2015 to 2035. Today the dead zone is more than triple that size. Our new­ly pub­lished mod­el­ing shows that it would take a 59 per­cent reduc­tion in the amount of nitro­gen enter­ing the Gulf of Mex­i­co to reach the task force’s goal.

Dis­solved oxy­gen lev­els in the Gulf of Mex­i­co in sum­mer 2010. (Info­graph­ic: NOAA)

The Chesa­peake Bay’s pol­lu­tion diet

States around the Chesa­peake Bay also strug­gled for decades to make vol­un­tary, incen­tive-based approach­es work. Their efforts were over­whelmed by the impacts of pop­u­la­tion growth and agri­cul­tur­al production. 

Frus­trat­ed by wors­en­ing con­di­tions, the states asked EPA in 2010 to estab­lish a total max­i­mum dai­ly load—a pol­lu­tion diet” with­in a reg­u­la­to­ry frame­work under the Clean Water Act that lim­its the amount of nutri­ents and sed­i­ment that can enter the bay. Bay states and the Dis­trict of Colum­bia then devel­oped imple­men­ta­tion plans and man­age­ment strate­gies detail­ing how and when each juris­dic­tion would meet its indi­vid­ual goals. 

Unlike vol­un­tary strate­gies, this approach has teeth. If states miss inter­im mile­stones for reduc­ing pol­lu­tants, EPA can impose back­stop mea­sures,” such as requir­ing addi­tion­al reduc­tions from point sources and with­hold­ing fed­er­al grant money. 

Agri­cul­tur­al groups, sup­port­ed by 21 states out­side the Chesa­peake water­shed, chal­lenged the total max­i­mum dai­ly load in court but lost. Between 2009 and 2015, loads of nitro­gen, phos­pho­rus and sed­i­ment in the bay dropped by 8 per­cent, 20 per­cent and 7 per­cent, respec­tive­ly. Under­wa­ter grass­es and the bay’s icon­ic blue crabs are start­ing to recov­er.

The Chesa­peake Bay’s $100 mil­lion blue crab fish­ery is start­ing to recov­er after years of decline due main­ly to water pol­lu­tion. (Image: Chesa­peake Bay Pro­gram)

No diet for Lake Erie

Envi­ron­men­tal groups recent­ly sued EPA to force stronger action on nutri­ent pol­lu­tion in Lake Erie’s west­ern basin, with sup­port from sev­er­al mem­bers of Con­gress and the Inter­na­tion­al Joint Com­mis­sion, which coor­di­nates efforts by the Unit­ed States and Cana­da. But EPA will appar­ent­ly write a total max­i­mum dai­ly load only if both Michi­gan and Ohio, the two key states in the west­ern basin water­shed, agree. (EPA Admin­is­tra­tor Scott Pruitt endorsed the Chesa­peake Bay total max­i­mum dai­ly load only because all six states in the bay’s water­shed sup­port­ed it.)

Michi­gan recent­ly declared its por­tion of Lake Erie impaired,” which is required to trig­ger a total max­i­mum dai­ly load. But Ohio declared only some of its shore­lines impaired, and EPA con­curred. So prospects for a recov­ery are slim.

EPA’s web page calls nutri­ent pol­lu­tion one of America’s most wide­spread, cost­ly and chal­leng­ing envi­ron­men­tal prob­lems.” But vol­un­tary action is not solv­ing it. And Pres­i­dent Trump’s EPA bud­get request would cut $165 mil­lion in grants to states to deal with non-point source pollution. 

As I have detailed before, tam­ing nutri­ent pol­lu­tion will require a broad nation­al approach that includes steps such as mod­i­fy­ing the Amer­i­can diet, chang­ing agri­cul­tur­al sup­ply chains and reduc­ing pro­duc­tion of corn-based ethanol. We also need to find the will to set legal­ly bind­ing lim­its when vol­un­tary steps aren’t enough.

Uni­ver­si­ty of Michi­gan pro­fes­sor Don­ald Scav­ia dis­cuss­es nutri­ent pol­lu­tion fore­casts. (Video: UM News Ser­vice / YouTube)

(“Nutri­ent Pol­lu­tion: Vol­un­tary Steps are Fail­ing to Shrink Algae Blooms and Dead Zones” was orig­i­nal­ly pub­lished on The Con­ver­sa­tion and is repost­ed on Rur­al Amer­i­ca In These Times under a Cre­ative Com­mons license.) 

Dis­clo­sure state­ment: Don­ald Scav­ia receives fund­ing from the Nation­al Sci­ence Foun­da­tion, Nation­al Ocean­ic and Atmos­pher­ic Admin­is­tra­tion, Envi­ron­men­tal Pro­tec­tion Agency, and the Erb Fam­i­ly Foundation.

Don­ald Scav­ia is Pro­fes­sor of Envi­ron­ment and Sus­tain­abil­i­ty and Pro­fes­sor of Envi­ron­men­tal Engi­neer­ing at the Uni­ver­si­ty of Michi­gan. Between 1975 and 2003, he worked as a senior sci­en­tist at the Nation­al Oceano­graph­ic and Atmos­pher­ic Admin­is­tra­tion (NOAA).
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