Plan urges city to OK sewers

Published 2:40 pm Thursday, October 2, 2008

CARNATION — A new plan to build sewers and a wastewater

treatment facility in Carnation promises to keep rivers clear while allowing

for more residential and business growth.

But it’s going to take time and money.

The proposal, conducted by American Engineering Corp.

of Redmond, was authorized by the city council and the local Sewer

Advisory Committee. It calls for the city to spend more than $3 million on

initial construction of a wastewater treatment facility and another $3.2 million on

the first phase of a city sewer system.

According to the proposal, the rest of the city would be phased in over

a 20-year period. The estimated total cost of those three phases is more

than $5.7 million.

In its executive summary to the proposal, the engineering firm says

the city of Carnation, which had a population of 1,725 in 1998-1999 and

grew at an annual rate of 3.8 percent from 1993 to 1999, can’t continue to

develop by solely using septic systems for homes and businesses. It

further projects Carnation’s population to reach 4,965 by 2020.

“The growth pressure in the area is beyond the control of the city,”

the summary states. “Other future needs such as home remodeling,

new-home construction, business expansion and buying and selling of homes

cannot occur unless adequate wastewater treatment is provided.”

At the same time, the downtown area is losing tenants. Businesses

are unable to expand or rebuild because septic systems can’t deal with it,

causing them to close shop.

“The need (for a sewer system) is critical,” said Mayor Bob

Patterson. “Our downtown is dying, and I

don’t think it could be brought back to life without a sewer.”

The plan calls for grinder pumps to deliver waste to

small-diameter, low-pressure mains, which would

then transport the waste to the treatment plant. The lines and mains of the

sewer system would only be 30 to 36 inches deep _ shallow enough to limit

the amount of digging needed to install them.

“It’s much easier to put in _ no big ditches, no gravity sewer,”

Patterson said.

Einar Gundersen, president of American Engineering, said the

firm was conscious of two important conditions when drawing up the

sewer proposal.

“They (city officials) want to make sure the facilities that are proposed

are cost-effective. And the city also wanted to make sure that the

facilities proposed actually improve water quality,” he said.

Patterson said the city wanted to keep the price, “as low as

possible, but we need to have a complete facility.” Information contained within

the proposal states residents of Carnation typically earn less than other

residents of King County.

The wastewater treatment plant would be located on a 10-acre

lot along West Entwistle Street. Sewage would go through a sludge

treatment process, and the remaining water would be disinfected and

discharged into the Snoqualmie River.

The river is home to anadromous _ including Chinook _ fish and

other species. But planners say the impact to the watershed would be minimal.

“Pollutant loading to the river will not be significant due to the

small quantity of sewage discharged and the enhanced removal capabilities of

the continuous flow-activated sludge treatment plant,” the proposal

states. In turn, the plant would also prevent contaminating the city’s groundwater.

“… A gradual phase-out of (septic) systems over the next 20

years will, likewise, alleviate groundwater contamination issues associated

with septic systems.”

Currently there are 700 septic systems in Carnation, and most of

them were built five to 20 years ago. The typical lifespan of a septic system

is 20 years, says American Engineering.

In its proposal, American Engineering suggests the first phase of

construction would include building the wastewater treatment facility

and sewers for “the Central Business District and the area generally

located west of the King County Parks Trail.”

Patterson said implementing the wastewater treatment system in

phases would help offset the financial impact of the problem. “We wanted to go

as small as we could the first time because of money.”

Phase 2 consists of building sewers to homes on the east side of

the city. Phase 3 includes two urban growth areas, one in north

Carnation, the other on the southwest corner of the city. And Phase 4 would

link homes and businesses in the eastern edge and southeast parts of the city

to the sewer system.

To pay for the system, the Carnation mayor said the city would go

after grants and low-interest loans, a process he’s already started. But

those connected to the sewer system will have to share some of the cost.

The costs for using the sewer system are broken down three ways.

Initially, those connected with the system would pay an assessment

based upon the square footage of the home or business. The assessment

includes two fees, one for the sewer system and another for the wastewater

treatment plant.

For example, an 8,000-square-foot home would pay an assessment

of $2,800 — $1,700 for collection and $1,100 for treatment. A

10,000-square-foot home would receive an assessment of $3,075 — $1,700

for collection and $1,375 for treatment.

Carnation businesses and homes hooked up to the system would

then pay $51 per month for each equivalent residential unit (ERU) they

use, which, says American Engineering, “… will cover the cost of

operations, maintenance, debt service, depreciation (replacement), taxes and

administration.” Those who use more than one ERU a month would pay

more. Water meters would be used to collect readings.

In addition, commercial uses that discharge high-strength waste

would be charged $63.75 per ERU.

Finally, a connection charge of about $4,000 per ERU will be

levied on those who didn’t pay the assessment and want to connect to the

system. The connection charge is primarily for vacant homes or other

properties and land developers who want to connect to the sewer system.

Gundersen said the reason for the higher charge is “they need to

be brought up to the same level, and then they need to pay for future expansion.”

In the future, the wastewater treatment plant could be updated to

produce reusable water that could be used to irrigate fields or in car

washes. Gundersen said the upgrade could be part of Phase 1, but it would cost

an additional $400,000 to $500,000.

Once the system is in place, Carnation would have the

infrastructure to attract businesses and

multi-unit, senior and low-income housing and allow the city to grow, but at the

pace it wants, Patterson said.

“We want to keep the rural area out here in the Valley,” he said.