Don’t quit this diet

A ‘pol­lu­tion diet’ is restor­ing health to the Ch­e­sa­peake Bay. The fed­eral gov­ern­ment should stick with it.

The Washington Post - - POWER POST -

NOT SO long ago, the Ch­e­sa­peake Bay seemed un­save­able. Pun­ished by years of pop­u­la­tion growth and pol­luted runoff, the bay’s wa­ters were murky. Cru­cial species were dy­ing off, and oxy­gen had be­come so scarce that toxic “dead zones” pro­lif­er­ated. Be­cause wa­ter flowed from so many states into the largest water­shed on the Eastern Se­aboard, an ef­fec­tive re­sponse was hard to imag­ine.

Yet now, nearly a decade af­ter the fed­eral gov­ern­ment stepped in with a not-par­tic­u­larly-oner­ous con­ser­va­tion ef­fort, the bay is re­bound­ing in a record­set­ting way. “We pro­vide con­clu­sive ev­i­dence that re­duc­ing dis­charges of ni­tro­gen, phos­pho­rus and other pol­lu­tants into the bay has pro­duced the largest resur­gence of un­der­wa­ter grasses ever recorded any­where,” the au­thors of a new study write. “This suc­cess shows that coastal ecosys­tems are re­silient and that con­certed ef­forts to re­duce nu­tri­ent pol­lu­tion can re­sult in sub­stan­tial im­prove­ments.”

The study re­ported that bay grasses have re­bounded four­fold since 1984, in­clud­ing in ar­eas that have not hosted sub­merged veg­e­ta­tion in years. Un­der­wa­ter grasses pro­vide a cru­cial habi­tat for a wide range of aquatic life, from sea­horses to snails. Mary­land’s fa­mous blue crabs feed on the life that the grasses sup­port.

The resur­gence in un­der­wa­ter veg­e­ta­tion is just one ben­e­fit of the “pol­lu­tion diet” the En­vi­ron­men­tal Pro­tec­tion Agency cre­ated for the bay’s water­shed, which in­cludes six states and the Dis­trict. By also al­ter­ing ur­ban sur­faces to pre­vent ex­ces­sive runoff and up­grad­ing waste­water treat­ment plants, the plan has helped cut ni­tro­gen pol­lu­tion 23 per­cent and phos­pho­rus pol­lu­tion 8 per­cent. “Nu­tri­ents over­fer­til­ize the bay, cre­at­ing huge blooms of al­gae that die and de­plete oxy­gen from the wa­ter,” the au­thors ex­plained. Th­ese nu­tri­ents also con­trib­ute to murk­i­ness that blocks the sun­light grasses need.

Part of what makes the Ch­e­sa­peake Bay pro­gram dis­tinct from more tra­di­tional pol­lu­tion con­trol ef­forts is its em­pha­sis on “nu­tri­ent trad­ing,” a flex­i­ble ap­proach to meet­ing the water­shed’s pol­lu­tion diet. This al­lows, say, a waste­water plant that would have to spend a great deal of money com­ply­ing with pol­lu­tion lim­its to pay farm­ers to plant cover crops that re­duce their nu­tri­ents in­stead. In this way, the eas­i­est pol­lu­tion re­duc­tions come first and the ex­pen­sive ones are given more time.

Pres­i­dent Trump has re­peat­edly in­sisted that he wants “crys­tal clear wa­ter.” The Ch­e­sa­peake Bay’s cleanup pro­gram is be­gin­ning to pro­duce just that, and it prom­ises to demon­strate the value of ef­fi­cient, mar­ket-based pol­lu­tion con­trols, too. Yet Mr. Trump ze­roed out the pro­gram in his bud­get. Thank­fully, Congress ap­pears poised to main­tain fund­ing.

Not­with­stand­ing its re­cent progress, the bay still suf­fers from sig­nif­i­cant oxy­gen-de­pleted dead zones, ex­ces­sive ni­tro­gen runoff and other prob­lems. Farm pol­lu­tion from fer­til­izer and ma­nure con­tin­ues to be a ma­jor chal­lenge. A sus­tained fed­eral com­mit­ment is es­sen­tial.

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