With the interlocal agreement and sewer rate structure between the City of Chehalis and the City of Napavine and Lewis County Sewer District (LCSD) 4 having last been updated in 2015, the Chehalis City Council unanimously approved a new interlocal agreement and rate structure during its regular meeting on Monday, Aug. 12.
This new agreement approved by Chehalis increases sewer rates for both Napavine and LCSD 4, which includes the Newaukum area and some properties on Logan Hill Road.
Chehalis Wastewater Superintendent Justin Phelps said the new rate structure followed the same methodology and calculations established in 2015. With inflation, costs for operating sewer systems have increased a lot since then, he said.
Previous sewer rates established in a 2015 interlocal agreement and meant to be used through 2020 had the City of Napavine paying $14,043 a month and LCSD 4 paying $5,178 a month, according to Chehalis Municipal Code.
The new interlocal agreement establishes sewer rates with Napavine paying $16,403 a month in 2024, $18,763 a month in 2025, $21,123 a month in 2026, $23,483 a month in 2027 and $25,844 a month in 2028.
LCSD 4 will now pay $6,004 a month in 2024, $6,829 a month in 2025, $7,655 a month in 2026, $8,480 a month in 2027 and $9,306 a month in 2028.
New rates will officially go into effect on Oct. 1. and will be effective through December 2028, at which time a new interlocal agreement will need to be created.
“The recalculation is detailed within that (new interlocal agreement),” Phelps said.
He said the new rates were calculated by the Sewer Operating Board.
According to the council’s meeting agenda report, the data utilized to calculate these rates include the past five years of sewer flow data, the past five years of applicable budget expenditure data from regional water reclamation and treatment facilities.
Additionally, calculations also included the ownership percentage of shared sewer interceptor lines with Chehalis having 96.4%, Napavine with 2.45% and LCSD 4 with 1.15%, and the ownership percentage of the Chehalis Regional Water Reclamation Facility (CRWRF) with Napavine having a 12% stake and LCSD 4 a 4% stake.
The actual calculation involves adding together:
• Treatment plant and poplar tree plantation budget expenditures minus utility costs times the percentage ownership stake in the CRWRF
• Treatment plant and poplar tree plantation budget expenditures times the percentage of sewer flow contribution
• The collection system budget minute utility cost times the ownership percentage of sewer interceptor lines
• The collection system budget utility costs times the percentage of flow contributed to the CRWRF
• 25% of the previous four calculations added together to account for administration costs
After these five figures were added together, the total was divided by 12 to determine the new monthly rates established in the new interlocal agreement.
The interlocal agreement will now undergo a second reading at the next council meeting before being sent to both the City of Napavine and LCSD 4 for final approval.
