Water Resources Director: Chris Graybeal
Our Mission To promote and protect the environment, preserve natural resources, and ensure the health and safety of our customers.
Granite Falls Wastewater Treatment Plant (WWTP) 2017 Bio Oxygen Demand (BOD) & Total Suspended Solids (TSS) Results 35.0 BOD mg/l TSS mg/l BOD Limit TSS Limit 30.0 25.0 20.0 15.0 10.0 5.0 0.0 Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec BOD mg/l 4.8 3.3 4.1 10.6 4.4 5.4 6.1 5.7 1.3 3.5 3.3 2.4 TSS mg/l 14.1 8.3 9.5 16.8 11.9 6.6 11.0 12.0 4.6 5.5 3.7 4.9 BOD Limit 30 30 30 30 25 25 25 25 25 25 30 30 TSS Limit 30 30 30 30 30 30 30 30 30 30 30 30 BOD & TSS are two of the main indicators of facility efficiency.
WWTP Average BOD & TSS Average Influent BOD for 2017 Average Effluent BOD for 2017 306 4.6 Permit Limit: 25 / 30 mg/l Average Influent TSS for 2017 Average Effluent TSS for 2017 144 9.1 Permit Limit: 30 mg/l Overall Treatment Plant Efficiency (Actual) Rate Efficiency of Treatment Plan (Design) 96.25% 87%
Granite Falls Wastewater Treatment Plant 2017 Ammonia Nitrogen Results 18 16 14 12 10 8 6 4 2 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Monthly Average mg/l 0.3 0.2 0.2 0.2 0.2 0.2 0.5 0.20 0.20 0.2 0.2 0.20 Daily Maximum mg/l 0.99 0.37 0.76 0.2 1.06 0.2 0.65 0.45 0.20 0.31 0.2 0.25 Monthly Summer Limit 6.2 6.2 6.2 6.2 6.2 6.2 6.2 Monthly Winter Limit 15.4 15.4 15.4 15.4 15.4 Monthly Average mg/l Daily Maximum mg/l Monthly Summer Limit Monthly Winter Limit Ammonia Nitrogen is also an indicator of the efficiency of the wastewater treatment process. Our facility operates well below the permitted limits for this chemical compound.
Granite Falls Wastewater Treatment Plant 2017 Fecal Coliform Results Monthly Average #100ml Monthly Limit Weekly Limit 450 400 350 300 250 200 150 100 50 0 Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Fecal Coliform are pathogenic organisms that must be removed from our discharge in order to meet state and federal standards. We have consistently discharged significantly less than our permitted limit.
100 Granite Falls Wastewater Treatment Plant Efficiency % 1993-2017 98 96 94 96 97 98 96 95 97 97 96 96 96 96 96 95 96 94 97 96 97 97 97 97 97 97 98 96.25 92 90 88 87 86 84 82 80 DESIGN RATED EFFICIENCY: 87% ACTUAL 2017 EFFICIENCY: 96.25%
There was an increase in discharge flow due to more rainfall events in 2017 which increased inflow and infiltration in the collection system. 200 TOTAL YEARLY FLOW 1987-2017 *TOTAL FLOW IN MILLION GALLONS 180 160 140 120 100 80 60 40 20 0
The Granite Falls Wastewater Treatment Plant treated 126,326,000 gallons, or an average of 346,098 per day, of wastewater while meeting all effluent limitations in our permit. In 2017, our wastewater flow increased by 12.6% from 2016 due to more rainfall events. The facility achieved a 96.25% combined efficiency removal rate and is operating below the permitted capacity.
Plant staff completed lab proficiency certification for field analysis during 2017. There were no compliance issues during 2017.
Upgrades were made to the chemical feed system with the addition of two new chemical feed pumps in the dechlorination building.
A new bulk material removal system was installed during the Wastewater plant upgrade to remove large debris at the headworks of the facility.
An additional sludge tank was added to the facility to expand sludge handling capabilities at the Wastewater Treatment Plant.
New eye wash safety showers were added in the chemical storage areas as part of the Wastewater Treatment Plant upgrade.
Monthly Water Treatment Plant Flow December November October September August July June May April March February January Minimum Daily Flow Average Flow Daily Maximum Daily Flow 0 500000 1000000 1500000 2000000
2016 & 2017 Flow Comparison 44000000 Chart Title 42000000 40000000 38000000 36000000 34000000 32000000 30000000 2017 2016 There was a 1.3% increase in water treated during 2017 due to construction and the July 2017 fire at One Putt.
Water Treatment Plant Chemicals Used In 2017 Chemical Amount Used Activated Carbon Aluminum Sulfate Chlorine (9.5 months) Sodium Hypochlorite (2.5 months) Fluoride Lime Slurry Polymer Potassium Permanganate 0 lbs. 19,891 gals 16,597 lbs. 1,677 lbs. 22,754 lbs. 24,275 gals 721 lbs. 1,149 lbs.
Water Treatment Plant Improvements Sludge handling capabilities were enhanced at the Water Treatment Plant which increased efficiency by allowing us to remove accumulated sludge during the treatment process.
Water Treatment Plant Improvements Polymer feed system pumps were upgraded to more efficient pumps.
Water Treatment Plant Improvements A total transition from chlorine gas to sodium hypochlorite has improved employee safety.
Employee Commitment During Times of Crisis Water Department employees demonstrated their dedication to the community and the Town by making themselves available to assist other departments during one of the largest fires in the history of the Town. Staff members also made themselves available during the tornado to ensure Water Department services continued for our customers. Water Plant staff worked closely with emergency services to provide an uninterrupted flow of 1.5 million gallons of water during the fire without a loss of water pressure to our customers. Water Plant staff reported for duty during the tornado event, even though some employees experienced damage to their personal property.
Training and Qualifications All Water Resources staff obtained their mandatory six hours of continuing education to maintain their certifications. One staff member obtained grade 2 wastewater certification. Two water staff plant staff members were promoted to positions of ORC and Backup ORC. All staff members attended required safety training.
In Conclusion Our Water Resources employees are operating both facilities at efficient levels. Drinking water and wastewater qualities continue to meet and/or exceed state and federal standards. We will continue to provide high quality of water to our customers, and return high quality water to the environment by the most efficient means available.