Since the mid 1960s, the use of treated effluent on golf courses has
been thought of as a solution to many developer's concerns with restrictive
water use laws and the general concern for use of expensive or unavailable
municipal potable water. The idea of using "effluent for irrigation" along
with recycling, reusing and resource conservation, continues to be vary popular.
The use of treated effluent has varying degrees of impact to golf courses
and has been relied upon as a primary source of water in the west and southwest,
particularly in arid regions. Golf courses have had considerable public scrutiny
with regard to their use of pesticides, fertilizers, ground water contamination,
wetlands degradation and a host of other water quality related issues. The
use of reclaimed water must be monitored to ensure there are no additional
concerns, and in some cases, the treated effluent can mitigate the use of
chemicals.
The opportunity for the City to recoup some of the treatment costs or offset
future temperature related costs is potentially a significant benefit to
the City. Our treated effluent is ideal for golf course irrigation use. Our
effluent is fully treated, has very low biological oxygen demands (BOD) and
low total suspended solids (TSS) and has been further filtered through the
membrane facility (May through November) to remove all remaining particulates.
Ashland does not have high levels of salts or other minerals, which can be
damaging to golf course turf.
Other factors also make this option very attractive. The City's impending
wastewater treatment plant permit will include temperature parameters and
limitations to continue discharging effluent to the creek. Effluent is generally
higher in temperature than the receiving creek and the new temperature standards
limit the amount of "heat" being discharged to the creek. Using the treated
effluent as irrigation for the golf course will eliminate some or all of
the discharge to the creek and reduce the added temperature element into
the creek. The water trading options that are being evaluated will offset
all or a significant portion of that loss so that the net effect of water
volume in the creek will be negligible.
Staff has discussed several options with respect to using treated effluent
for golf course irrigation:
1) Golf course volumes: It is understood that the golf course expects to
use 1.0 - 1.25 million gallons of water per day (mgd). This volume would
need to be fully defined. Any amount of evaporation from the ponds would
need to be factored into the amount the City delivers to the pond to ensure
there is adequate water for the irrigation need. The City would deliver the
treated effluent at a constant rate through the day. Any heavy watering periods
would have to be factored into this need. The City could adjust the water
delivery to meet the needs of the golf course.
2) Creek recharge option: The City produces an average of 2.1 million gallons
of treated effluent a day. It is conceptually possible that the City could
send all of the effluent to the Billings pond and that the golf course could
release the deeper cooler pond water back to the creek, but this is something
that would have to be evaluated further and permitted through DEQ.
3) Infrastructure costs: It is understood that the City would deliver treated
effluent to the pond and that the golf course would irrigate out of the pond.
The infrastructure cost and who pays for the costs to build the pump station
and pipeline to the ponds has not been determined. It is expected that the
proposed Billings golf course would pay the costs to pump the water to the
ponds.
4) Membrane process: Typically golf courses are not watered year-around,
except in very arid regions. Ashland can experience arid periods. It may
be necessary to intermittently water the golf course in the shoulder months
of March and April as well as November. If this were the case, the City would
have to use the membrane treatment facility to treat water for reuse. Currently,
the City is required to use the membrane filters from May 1st through November
30th. Using the membranes for effluent reuse other than these specified times
would add cost to the treatment process. The cost to filter effluent through
the membrane facility is an additional $0.29 per 1000 gallons.
5) Chemical use: There is potential to adjust the alum dosage to the membrane
facility. The golf course might be able to use more of the phosphorous that
is naturally in our effluent and we might not be required to precipitate
out all of the phosphorous as we are doing for creek discharges. This option
would have to be explored with the golf course and approved through DEQ.
6) Water trading opportunities: At this point, the Billings property has
water rights from three locations; Wrights Creek, Ashland Creek and Talent
Irrigation District. At a minimum, it is expected that the water rights from
Ashland Creek and TID would be leased to the City to be used as in-stream
rights. This might be facilitated through the Oregon Water Trust or other
body to ensure that this amount be held as an in-stream right. It is the
City's understanding that the proposed Billings golf course property has
irrigation water rights totaling 64 acres/ 0.8 cfs off of Ashland Creek and
38 acres / 0.485 cfs off of Wrights Creek. In addition, there is 13.5 acres
of land that has a seasonal TID irrigation right. There is a second TID right
on a separate Billings parcel totaling 19.9 acres, but that is not included
in this discussion as there is question as to which parcel that specifically
pertains to.
7) Effluent Level IV designation: The City is currently negotiating a new
permit for the treatment plant and discharge limits with DEQ. The option
remains open for a discharge for reclaimed water (effluent reuse). There
is one area that may need further clarification from DEQ with regard to the
effluent quality. The City's disinfection process changed from chlorine gas
to uv (ultraviolet) disinfection. As such there is no chlorine residual in
the effluent. Also, the uv disinfection system is ahead of the membrane filters,
which is not typical as most disinfection processes are the last piece of
the treatment process. As such, the city is negotiating with DEQ on the "level
IV - unrestricted use" label for the treated effluent. DEQ has indicated
that it may require the City to install a low level sodium hypochlorite dose
as the effluent is pumped to the ponds. This detail will need to be worked
out prior to final agreements with the Billings golf course and DEQ for reuse.
8) Golf course compliance: The proposed Billings golf course will have to
comply with DEQ's requirements for all other reuse components including an
irrigation reuse plan to ensure the property is not overloaded with nutrients
and that there is no impairment of existing or potential ground water. Any
point source discharge (ie: from the ponds) the golf course property will
require a separate permit.
9) Golf Course benefit: The benefit to the proposed Billing's ranch property
is in the cost of water and in consistent delivery. Billings would likely
continue to pay for it's TID water (roughly $600 per season) and "trade"
these costs with the City's effluent. However for comparison, if this property
was irrigated with potable water at a cost of $1.00 per 1000 gallons, their
cost would be over $100 per day. The 13.5 acres of TID water translates to
only 12 million gallons total, which is not adequate for the golf course.
The additional Wrights Creek and Ashland Creek water would supply as much
as 830,500 gallons per day, not enough for summer demands for the golf course.
10) City benefits: The benefit of using treated effluent is two fold; one,
the effluent is reused so that the temperature impacts to a water quality
limited stream are reduced, and two, there is a benefit by retaining 0.8
cfs in Ashland Creek dedicated for in-stream benefit and another 0.485 cfs
in Bear Creek (at about Jackson Road) dedicated for in-steam benefit.
[For comparison, 1.285 cfs is 830,500 gallons per day. The total treatment
plant effluent is 2.2 mgd or 3.4 cfs; 1.0 mgd is 1.55 cfs.] |
